1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * f_fs.c -- user mode file system API for USB composite function controllers 4 * 5 * Copyright (C) 2010 Samsung Electronics 6 * Author: Michal Nazarewicz <mina86@mina86.com> 7 * 8 * Based on inode.c (GadgetFS) which was: 9 * Copyright (C) 2003-2004 David Brownell 10 * Copyright (C) 2003 Agilent Technologies 11 */ 12 13 14 /* #define DEBUG */ 15 /* #define VERBOSE_DEBUG */ 16 17 #include <linux/blkdev.h> 18 #include <linux/pagemap.h> 19 #include <linux/export.h> 20 #include <linux/fs_parser.h> 21 #include <linux/hid.h> 22 #include <linux/mm.h> 23 #include <linux/module.h> 24 #include <linux/scatterlist.h> 25 #include <linux/sched/signal.h> 26 #include <linux/uio.h> 27 #include <linux/vmalloc.h> 28 #include <asm/unaligned.h> 29 30 #include <linux/usb/ccid.h> 31 #include <linux/usb/composite.h> 32 #include <linux/usb/functionfs.h> 33 34 #include <linux/aio.h> 35 #include <linux/kthread.h> 36 #include <linux/poll.h> 37 #include <linux/eventfd.h> 38 39 #include "u_fs.h" 40 #include "u_f.h" 41 #include "u_os_desc.h" 42 #include "configfs.h" 43 44 #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ 45 46 /* Reference counter handling */ 47 static void ffs_data_get(struct ffs_data *ffs); 48 static void ffs_data_put(struct ffs_data *ffs); 49 /* Creates new ffs_data object. */ 50 static struct ffs_data *__must_check ffs_data_new(const char *dev_name) 51 __attribute__((malloc)); 52 53 /* Opened counter handling. */ 54 static void ffs_data_opened(struct ffs_data *ffs); 55 static void ffs_data_closed(struct ffs_data *ffs); 56 57 /* Called with ffs->mutex held; take over ownership of data. */ 58 static int __must_check 59 __ffs_data_got_descs(struct ffs_data *ffs, char *data, size_t len); 60 static int __must_check 61 __ffs_data_got_strings(struct ffs_data *ffs, char *data, size_t len); 62 63 64 /* The function structure ***************************************************/ 65 66 struct ffs_ep; 67 68 struct ffs_function { 69 struct usb_configuration *conf; 70 struct usb_gadget *gadget; 71 struct ffs_data *ffs; 72 73 struct ffs_ep *eps; 74 u8 eps_revmap[16]; 75 short *interfaces_nums; 76 77 struct usb_function function; 78 }; 79 80 81 static struct ffs_function *ffs_func_from_usb(struct usb_function *f) 82 { 83 return container_of(f, struct ffs_function, function); 84 } 85 86 87 static inline enum ffs_setup_state 88 ffs_setup_state_clear_cancelled(struct ffs_data *ffs) 89 { 90 return (enum ffs_setup_state) 91 cmpxchg(&ffs->setup_state, FFS_SETUP_CANCELLED, FFS_NO_SETUP); 92 } 93 94 95 static void ffs_func_eps_disable(struct ffs_function *func); 96 static int __must_check ffs_func_eps_enable(struct ffs_function *func); 97 98 static int ffs_func_bind(struct usb_configuration *, 99 struct usb_function *); 100 static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); 101 static void ffs_func_disable(struct usb_function *); 102 static int ffs_func_setup(struct usb_function *, 103 const struct usb_ctrlrequest *); 104 static bool ffs_func_req_match(struct usb_function *, 105 const struct usb_ctrlrequest *, 106 bool config0); 107 static void ffs_func_suspend(struct usb_function *); 108 static void ffs_func_resume(struct usb_function *); 109 110 111 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num); 112 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf); 113 114 115 /* The endpoints structures *************************************************/ 116 117 struct ffs_ep { 118 struct usb_ep *ep; /* P: ffs->eps_lock */ 119 struct usb_request *req; /* P: epfile->mutex */ 120 121 /* [0]: full speed, [1]: high speed, [2]: super speed */ 122 struct usb_endpoint_descriptor *descs[3]; 123 124 u8 num; 125 }; 126 127 struct ffs_epfile { 128 /* Protects ep->ep and ep->req. */ 129 struct mutex mutex; 130 131 struct ffs_data *ffs; 132 struct ffs_ep *ep; /* P: ffs->eps_lock */ 133 134 struct dentry *dentry; 135 136 /* 137 * Buffer for holding data from partial reads which may happen since 138 * we’re rounding user read requests to a multiple of a max packet size. 139 * 140 * The pointer is initialised with NULL value and may be set by 141 * __ffs_epfile_read_data function to point to a temporary buffer. 142 * 143 * In normal operation, calls to __ffs_epfile_read_buffered will consume 144 * data from said buffer and eventually free it. Importantly, while the 145 * function is using the buffer, it sets the pointer to NULL. This is 146 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered 147 * can never run concurrently (they are synchronised by epfile->mutex) 148 * so the latter will not assign a new value to the pointer. 149 * 150 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is 151 * valid) and sets the pointer to READ_BUFFER_DROP value. This special 152 * value is crux of the synchronisation between ffs_func_eps_disable and 153 * __ffs_epfile_read_data. 154 * 155 * Once __ffs_epfile_read_data is about to finish it will try to set the 156 * pointer back to its old value (as described above), but seeing as the 157 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free 158 * the buffer. 159 * 160 * == State transitions == 161 * 162 * • ptr == NULL: (initial state) 163 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP 164 * ◦ __ffs_epfile_read_buffered: nop 165 * ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf 166 * ◦ reading finishes: n/a, not in ‘and reading’ state 167 * • ptr == DROP: 168 * ◦ __ffs_epfile_read_buffer_free: nop 169 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL 170 * ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop 171 * ◦ reading finishes: n/a, not in ‘and reading’ state 172 * • ptr == buf: 173 * ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP 174 * ◦ __ffs_epfile_read_buffered: go to ptr == NULL and reading 175 * ◦ __ffs_epfile_read_data: n/a, __ffs_epfile_read_buffered 176 * is always called first 177 * ◦ reading finishes: n/a, not in ‘and reading’ state 178 * • ptr == NULL and reading: 179 * ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading 180 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 181 * ◦ __ffs_epfile_read_data: n/a, mutex is held 182 * ◦ reading finishes and … 183 * … all data read: free buf, go to ptr == NULL 184 * … otherwise: go to ptr == buf and reading 185 * • ptr == DROP and reading: 186 * ◦ __ffs_epfile_read_buffer_free: nop 187 * ◦ __ffs_epfile_read_buffered: n/a, mutex is held 188 * ◦ __ffs_epfile_read_data: n/a, mutex is held 189 * ◦ reading finishes: free buf, go to ptr == DROP 190 */ 191 struct ffs_buffer *read_buffer; 192 #define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN)) 193 194 char name[5]; 195 196 unsigned char in; /* P: ffs->eps_lock */ 197 unsigned char isoc; /* P: ffs->eps_lock */ 198 199 unsigned char _pad; 200 }; 201 202 struct ffs_buffer { 203 size_t length; 204 char *data; 205 char storage[]; 206 }; 207 208 /* ffs_io_data structure ***************************************************/ 209 210 struct ffs_io_data { 211 bool aio; 212 bool read; 213 214 struct kiocb *kiocb; 215 struct iov_iter data; 216 const void *to_free; 217 char *buf; 218 219 struct mm_struct *mm; 220 struct work_struct work; 221 222 struct usb_ep *ep; 223 struct usb_request *req; 224 struct sg_table sgt; 225 bool use_sg; 226 227 struct ffs_data *ffs; 228 229 int status; 230 struct completion done; 231 }; 232 233 struct ffs_desc_helper { 234 struct ffs_data *ffs; 235 unsigned interfaces_count; 236 unsigned eps_count; 237 }; 238 239 static int __must_check ffs_epfiles_create(struct ffs_data *ffs); 240 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count); 241 242 static struct dentry * 243 ffs_sb_create_file(struct super_block *sb, const char *name, void *data, 244 const struct file_operations *fops); 245 246 /* Devices management *******************************************************/ 247 248 DEFINE_MUTEX(ffs_lock); 249 EXPORT_SYMBOL_GPL(ffs_lock); 250 251 static struct ffs_dev *_ffs_find_dev(const char *name); 252 static struct ffs_dev *_ffs_alloc_dev(void); 253 static void _ffs_free_dev(struct ffs_dev *dev); 254 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data); 255 static void ffs_release_dev(struct ffs_dev *ffs_dev); 256 static int ffs_ready(struct ffs_data *ffs); 257 static void ffs_closed(struct ffs_data *ffs); 258 259 /* Misc helper functions ****************************************************/ 260 261 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 262 __attribute__((warn_unused_result, nonnull)); 263 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 264 __attribute__((warn_unused_result, nonnull)); 265 266 267 /* Control file aka ep0 *****************************************************/ 268 269 static void ffs_ep0_complete(struct usb_ep *ep, struct usb_request *req) 270 { 271 struct ffs_data *ffs = req->context; 272 273 complete(&ffs->ep0req_completion); 274 } 275 276 static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len) 277 __releases(&ffs->ev.waitq.lock) 278 { 279 struct usb_request *req = ffs->ep0req; 280 int ret; 281 282 if (!req) { 283 spin_unlock_irq(&ffs->ev.waitq.lock); 284 return -EINVAL; 285 } 286 287 req->zero = len < le16_to_cpu(ffs->ev.setup.wLength); 288 289 spin_unlock_irq(&ffs->ev.waitq.lock); 290 291 req->buf = data; 292 req->length = len; 293 294 /* 295 * UDC layer requires to provide a buffer even for ZLP, but should 296 * not use it at all. Let's provide some poisoned pointer to catch 297 * possible bug in the driver. 298 */ 299 if (req->buf == NULL) 300 req->buf = (void *)0xDEADBABE; 301 302 reinit_completion(&ffs->ep0req_completion); 303 304 ret = usb_ep_queue(ffs->gadget->ep0, req, GFP_ATOMIC); 305 if (ret < 0) 306 return ret; 307 308 ret = wait_for_completion_interruptible(&ffs->ep0req_completion); 309 if (ret) { 310 usb_ep_dequeue(ffs->gadget->ep0, req); 311 return -EINTR; 312 } 313 314 ffs->setup_state = FFS_NO_SETUP; 315 return req->status ? req->status : req->actual; 316 } 317 318 static int __ffs_ep0_stall(struct ffs_data *ffs) 319 { 320 if (ffs->ev.can_stall) { 321 pr_vdebug("ep0 stall\n"); 322 usb_ep_set_halt(ffs->gadget->ep0); 323 ffs->setup_state = FFS_NO_SETUP; 324 return -EL2HLT; 325 } else { 326 pr_debug("bogus ep0 stall!\n"); 327 return -ESRCH; 328 } 329 } 330 331 static ssize_t ffs_ep0_write(struct file *file, const char __user *buf, 332 size_t len, loff_t *ptr) 333 { 334 struct ffs_data *ffs = file->private_data; 335 ssize_t ret; 336 char *data; 337 338 ENTER(); 339 340 /* Fast check if setup was canceled */ 341 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 342 return -EIDRM; 343 344 /* Acquire mutex */ 345 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 346 if (ret < 0) 347 return ret; 348 349 /* Check state */ 350 switch (ffs->state) { 351 case FFS_READ_DESCRIPTORS: 352 case FFS_READ_STRINGS: 353 /* Copy data */ 354 if (len < 16) { 355 ret = -EINVAL; 356 break; 357 } 358 359 data = ffs_prepare_buffer(buf, len); 360 if (IS_ERR(data)) { 361 ret = PTR_ERR(data); 362 break; 363 } 364 365 /* Handle data */ 366 if (ffs->state == FFS_READ_DESCRIPTORS) { 367 pr_info("read descriptors\n"); 368 ret = __ffs_data_got_descs(ffs, data, len); 369 if (ret < 0) 370 break; 371 372 ffs->state = FFS_READ_STRINGS; 373 ret = len; 374 } else { 375 pr_info("read strings\n"); 376 ret = __ffs_data_got_strings(ffs, data, len); 377 if (ret < 0) 378 break; 379 380 ret = ffs_epfiles_create(ffs); 381 if (ret) { 382 ffs->state = FFS_CLOSING; 383 break; 384 } 385 386 ffs->state = FFS_ACTIVE; 387 mutex_unlock(&ffs->mutex); 388 389 ret = ffs_ready(ffs); 390 if (ret < 0) { 391 ffs->state = FFS_CLOSING; 392 return ret; 393 } 394 395 return len; 396 } 397 break; 398 399 case FFS_ACTIVE: 400 data = NULL; 401 /* 402 * We're called from user space, we can use _irq 403 * rather then _irqsave 404 */ 405 spin_lock_irq(&ffs->ev.waitq.lock); 406 switch (ffs_setup_state_clear_cancelled(ffs)) { 407 case FFS_SETUP_CANCELLED: 408 ret = -EIDRM; 409 goto done_spin; 410 411 case FFS_NO_SETUP: 412 ret = -ESRCH; 413 goto done_spin; 414 415 case FFS_SETUP_PENDING: 416 break; 417 } 418 419 /* FFS_SETUP_PENDING */ 420 if (!(ffs->ev.setup.bRequestType & USB_DIR_IN)) { 421 spin_unlock_irq(&ffs->ev.waitq.lock); 422 ret = __ffs_ep0_stall(ffs); 423 break; 424 } 425 426 /* FFS_SETUP_PENDING and not stall */ 427 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 428 429 spin_unlock_irq(&ffs->ev.waitq.lock); 430 431 data = ffs_prepare_buffer(buf, len); 432 if (IS_ERR(data)) { 433 ret = PTR_ERR(data); 434 break; 435 } 436 437 spin_lock_irq(&ffs->ev.waitq.lock); 438 439 /* 440 * We are guaranteed to be still in FFS_ACTIVE state 441 * but the state of setup could have changed from 442 * FFS_SETUP_PENDING to FFS_SETUP_CANCELLED so we need 443 * to check for that. If that happened we copied data 444 * from user space in vain but it's unlikely. 445 * 446 * For sure we are not in FFS_NO_SETUP since this is 447 * the only place FFS_SETUP_PENDING -> FFS_NO_SETUP 448 * transition can be performed and it's protected by 449 * mutex. 450 */ 451 if (ffs_setup_state_clear_cancelled(ffs) == 452 FFS_SETUP_CANCELLED) { 453 ret = -EIDRM; 454 done_spin: 455 spin_unlock_irq(&ffs->ev.waitq.lock); 456 } else { 457 /* unlocks spinlock */ 458 ret = __ffs_ep0_queue_wait(ffs, data, len); 459 } 460 kfree(data); 461 break; 462 463 default: 464 ret = -EBADFD; 465 break; 466 } 467 468 mutex_unlock(&ffs->mutex); 469 return ret; 470 } 471 472 /* Called with ffs->ev.waitq.lock and ffs->mutex held, both released on exit. */ 473 static ssize_t __ffs_ep0_read_events(struct ffs_data *ffs, char __user *buf, 474 size_t n) 475 __releases(&ffs->ev.waitq.lock) 476 { 477 /* 478 * n cannot be bigger than ffs->ev.count, which cannot be bigger than 479 * size of ffs->ev.types array (which is four) so that's how much space 480 * we reserve. 481 */ 482 struct usb_functionfs_event events[ARRAY_SIZE(ffs->ev.types)]; 483 const size_t size = n * sizeof *events; 484 unsigned i = 0; 485 486 memset(events, 0, size); 487 488 do { 489 events[i].type = ffs->ev.types[i]; 490 if (events[i].type == FUNCTIONFS_SETUP) { 491 events[i].u.setup = ffs->ev.setup; 492 ffs->setup_state = FFS_SETUP_PENDING; 493 } 494 } while (++i < n); 495 496 ffs->ev.count -= n; 497 if (ffs->ev.count) 498 memmove(ffs->ev.types, ffs->ev.types + n, 499 ffs->ev.count * sizeof *ffs->ev.types); 500 501 spin_unlock_irq(&ffs->ev.waitq.lock); 502 mutex_unlock(&ffs->mutex); 503 504 return copy_to_user(buf, events, size) ? -EFAULT : size; 505 } 506 507 static ssize_t ffs_ep0_read(struct file *file, char __user *buf, 508 size_t len, loff_t *ptr) 509 { 510 struct ffs_data *ffs = file->private_data; 511 char *data = NULL; 512 size_t n; 513 int ret; 514 515 ENTER(); 516 517 /* Fast check if setup was canceled */ 518 if (ffs_setup_state_clear_cancelled(ffs) == FFS_SETUP_CANCELLED) 519 return -EIDRM; 520 521 /* Acquire mutex */ 522 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 523 if (ret < 0) 524 return ret; 525 526 /* Check state */ 527 if (ffs->state != FFS_ACTIVE) { 528 ret = -EBADFD; 529 goto done_mutex; 530 } 531 532 /* 533 * We're called from user space, we can use _irq rather then 534 * _irqsave 535 */ 536 spin_lock_irq(&ffs->ev.waitq.lock); 537 538 switch (ffs_setup_state_clear_cancelled(ffs)) { 539 case FFS_SETUP_CANCELLED: 540 ret = -EIDRM; 541 break; 542 543 case FFS_NO_SETUP: 544 n = len / sizeof(struct usb_functionfs_event); 545 if (!n) { 546 ret = -EINVAL; 547 break; 548 } 549 550 if ((file->f_flags & O_NONBLOCK) && !ffs->ev.count) { 551 ret = -EAGAIN; 552 break; 553 } 554 555 if (wait_event_interruptible_exclusive_locked_irq(ffs->ev.waitq, 556 ffs->ev.count)) { 557 ret = -EINTR; 558 break; 559 } 560 561 /* unlocks spinlock */ 562 return __ffs_ep0_read_events(ffs, buf, 563 min(n, (size_t)ffs->ev.count)); 564 565 case FFS_SETUP_PENDING: 566 if (ffs->ev.setup.bRequestType & USB_DIR_IN) { 567 spin_unlock_irq(&ffs->ev.waitq.lock); 568 ret = __ffs_ep0_stall(ffs); 569 goto done_mutex; 570 } 571 572 len = min(len, (size_t)le16_to_cpu(ffs->ev.setup.wLength)); 573 574 spin_unlock_irq(&ffs->ev.waitq.lock); 575 576 if (len) { 577 data = kmalloc(len, GFP_KERNEL); 578 if (!data) { 579 ret = -ENOMEM; 580 goto done_mutex; 581 } 582 } 583 584 spin_lock_irq(&ffs->ev.waitq.lock); 585 586 /* See ffs_ep0_write() */ 587 if (ffs_setup_state_clear_cancelled(ffs) == 588 FFS_SETUP_CANCELLED) { 589 ret = -EIDRM; 590 break; 591 } 592 593 /* unlocks spinlock */ 594 ret = __ffs_ep0_queue_wait(ffs, data, len); 595 if ((ret > 0) && (copy_to_user(buf, data, len))) 596 ret = -EFAULT; 597 goto done_mutex; 598 599 default: 600 ret = -EBADFD; 601 break; 602 } 603 604 spin_unlock_irq(&ffs->ev.waitq.lock); 605 done_mutex: 606 mutex_unlock(&ffs->mutex); 607 kfree(data); 608 return ret; 609 } 610 611 static int ffs_ep0_open(struct inode *inode, struct file *file) 612 { 613 struct ffs_data *ffs = inode->i_private; 614 615 ENTER(); 616 617 if (ffs->state == FFS_CLOSING) 618 return -EBUSY; 619 620 file->private_data = ffs; 621 ffs_data_opened(ffs); 622 623 return stream_open(inode, file); 624 } 625 626 static int ffs_ep0_release(struct inode *inode, struct file *file) 627 { 628 struct ffs_data *ffs = file->private_data; 629 630 ENTER(); 631 632 ffs_data_closed(ffs); 633 634 return 0; 635 } 636 637 static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 638 { 639 struct ffs_data *ffs = file->private_data; 640 struct usb_gadget *gadget = ffs->gadget; 641 long ret; 642 643 ENTER(); 644 645 if (code == FUNCTIONFS_INTERFACE_REVMAP) { 646 struct ffs_function *func = ffs->func; 647 ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; 648 } else if (gadget && gadget->ops->ioctl) { 649 ret = gadget->ops->ioctl(gadget, code, value); 650 } else { 651 ret = -ENOTTY; 652 } 653 654 return ret; 655 } 656 657 static __poll_t ffs_ep0_poll(struct file *file, poll_table *wait) 658 { 659 struct ffs_data *ffs = file->private_data; 660 __poll_t mask = EPOLLWRNORM; 661 int ret; 662 663 poll_wait(file, &ffs->ev.waitq, wait); 664 665 ret = ffs_mutex_lock(&ffs->mutex, file->f_flags & O_NONBLOCK); 666 if (ret < 0) 667 return mask; 668 669 switch (ffs->state) { 670 case FFS_READ_DESCRIPTORS: 671 case FFS_READ_STRINGS: 672 mask |= EPOLLOUT; 673 break; 674 675 case FFS_ACTIVE: 676 switch (ffs->setup_state) { 677 case FFS_NO_SETUP: 678 if (ffs->ev.count) 679 mask |= EPOLLIN; 680 break; 681 682 case FFS_SETUP_PENDING: 683 case FFS_SETUP_CANCELLED: 684 mask |= (EPOLLIN | EPOLLOUT); 685 break; 686 } 687 break; 688 689 case FFS_CLOSING: 690 break; 691 case FFS_DEACTIVATED: 692 break; 693 } 694 695 mutex_unlock(&ffs->mutex); 696 697 return mask; 698 } 699 700 static const struct file_operations ffs_ep0_operations = { 701 .llseek = no_llseek, 702 703 .open = ffs_ep0_open, 704 .write = ffs_ep0_write, 705 .read = ffs_ep0_read, 706 .release = ffs_ep0_release, 707 .unlocked_ioctl = ffs_ep0_ioctl, 708 .poll = ffs_ep0_poll, 709 }; 710 711 712 /* "Normal" endpoints operations ********************************************/ 713 714 static void ffs_epfile_io_complete(struct usb_ep *_ep, struct usb_request *req) 715 { 716 struct ffs_io_data *io_data = req->context; 717 718 ENTER(); 719 if (req->status) 720 io_data->status = req->status; 721 else 722 io_data->status = req->actual; 723 724 complete(&io_data->done); 725 } 726 727 static ssize_t ffs_copy_to_iter(void *data, int data_len, struct iov_iter *iter) 728 { 729 ssize_t ret = copy_to_iter(data, data_len, iter); 730 if (ret == data_len) 731 return ret; 732 733 if (iov_iter_count(iter)) 734 return -EFAULT; 735 736 /* 737 * Dear user space developer! 738 * 739 * TL;DR: To stop getting below error message in your kernel log, change 740 * user space code using functionfs to align read buffers to a max 741 * packet size. 742 * 743 * Some UDCs (e.g. dwc3) require request sizes to be a multiple of a max 744 * packet size. When unaligned buffer is passed to functionfs, it 745 * internally uses a larger, aligned buffer so that such UDCs are happy. 746 * 747 * Unfortunately, this means that host may send more data than was 748 * requested in read(2) system call. f_fs doesn’t know what to do with 749 * that excess data so it simply drops it. 750 * 751 * Was the buffer aligned in the first place, no such problem would 752 * happen. 753 * 754 * Data may be dropped only in AIO reads. Synchronous reads are handled 755 * by splitting a request into multiple parts. This splitting may still 756 * be a problem though so it’s likely best to align the buffer 757 * regardless of it being AIO or not.. 758 * 759 * This only affects OUT endpoints, i.e. reading data with a read(2), 760 * aio_read(2) etc. system calls. Writing data to an IN endpoint is not 761 * affected. 762 */ 763 pr_err("functionfs read size %d > requested size %zd, dropping excess data. " 764 "Align read buffer size to max packet size to avoid the problem.\n", 765 data_len, ret); 766 767 return ret; 768 } 769 770 /* 771 * allocate a virtually contiguous buffer and create a scatterlist describing it 772 * @sg_table - pointer to a place to be filled with sg_table contents 773 * @size - required buffer size 774 */ 775 static void *ffs_build_sg_list(struct sg_table *sgt, size_t sz) 776 { 777 struct page **pages; 778 void *vaddr, *ptr; 779 unsigned int n_pages; 780 int i; 781 782 vaddr = vmalloc(sz); 783 if (!vaddr) 784 return NULL; 785 786 n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT; 787 pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL); 788 if (!pages) { 789 vfree(vaddr); 790 791 return NULL; 792 } 793 for (i = 0, ptr = vaddr; i < n_pages; ++i, ptr += PAGE_SIZE) 794 pages[i] = vmalloc_to_page(ptr); 795 796 if (sg_alloc_table_from_pages(sgt, pages, n_pages, 0, sz, GFP_KERNEL)) { 797 kvfree(pages); 798 vfree(vaddr); 799 800 return NULL; 801 } 802 kvfree(pages); 803 804 return vaddr; 805 } 806 807 static inline void *ffs_alloc_buffer(struct ffs_io_data *io_data, 808 size_t data_len) 809 { 810 if (io_data->use_sg) 811 return ffs_build_sg_list(&io_data->sgt, data_len); 812 813 return kmalloc(data_len, GFP_KERNEL); 814 } 815 816 static inline void ffs_free_buffer(struct ffs_io_data *io_data) 817 { 818 if (!io_data->buf) 819 return; 820 821 if (io_data->use_sg) { 822 sg_free_table(&io_data->sgt); 823 vfree(io_data->buf); 824 } else { 825 kfree(io_data->buf); 826 } 827 } 828 829 static void ffs_user_copy_worker(struct work_struct *work) 830 { 831 struct ffs_io_data *io_data = container_of(work, struct ffs_io_data, 832 work); 833 int ret = io_data->req->status ? io_data->req->status : 834 io_data->req->actual; 835 bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; 836 837 if (io_data->read && ret > 0) { 838 kthread_use_mm(io_data->mm); 839 ret = ffs_copy_to_iter(io_data->buf, ret, &io_data->data); 840 kthread_unuse_mm(io_data->mm); 841 } 842 843 io_data->kiocb->ki_complete(io_data->kiocb, ret); 844 845 if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) 846 eventfd_signal(io_data->ffs->ffs_eventfd, 1); 847 848 usb_ep_free_request(io_data->ep, io_data->req); 849 850 if (io_data->read) 851 kfree(io_data->to_free); 852 ffs_free_buffer(io_data); 853 kfree(io_data); 854 } 855 856 static void ffs_epfile_async_io_complete(struct usb_ep *_ep, 857 struct usb_request *req) 858 { 859 struct ffs_io_data *io_data = req->context; 860 struct ffs_data *ffs = io_data->ffs; 861 862 ENTER(); 863 864 INIT_WORK(&io_data->work, ffs_user_copy_worker); 865 queue_work(ffs->io_completion_wq, &io_data->work); 866 } 867 868 static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile) 869 { 870 /* 871 * See comment in struct ffs_epfile for full read_buffer pointer 872 * synchronisation story. 873 */ 874 struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP); 875 if (buf && buf != READ_BUFFER_DROP) 876 kfree(buf); 877 } 878 879 /* Assumes epfile->mutex is held. */ 880 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile, 881 struct iov_iter *iter) 882 { 883 /* 884 * Null out epfile->read_buffer so ffs_func_eps_disable does not free 885 * the buffer while we are using it. See comment in struct ffs_epfile 886 * for full read_buffer pointer synchronisation story. 887 */ 888 struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL); 889 ssize_t ret; 890 if (!buf || buf == READ_BUFFER_DROP) 891 return 0; 892 893 ret = copy_to_iter(buf->data, buf->length, iter); 894 if (buf->length == ret) { 895 kfree(buf); 896 return ret; 897 } 898 899 if (iov_iter_count(iter)) { 900 ret = -EFAULT; 901 } else { 902 buf->length -= ret; 903 buf->data += ret; 904 } 905 906 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 907 kfree(buf); 908 909 return ret; 910 } 911 912 /* Assumes epfile->mutex is held. */ 913 static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile, 914 void *data, int data_len, 915 struct iov_iter *iter) 916 { 917 struct ffs_buffer *buf; 918 919 ssize_t ret = copy_to_iter(data, data_len, iter); 920 if (data_len == ret) 921 return ret; 922 923 if (iov_iter_count(iter)) 924 return -EFAULT; 925 926 /* See ffs_copy_to_iter for more context. */ 927 pr_warn("functionfs read size %d > requested size %zd, splitting request into multiple reads.", 928 data_len, ret); 929 930 data_len -= ret; 931 buf = kmalloc(struct_size(buf, storage, data_len), GFP_KERNEL); 932 if (!buf) 933 return -ENOMEM; 934 buf->length = data_len; 935 buf->data = buf->storage; 936 memcpy(buf->storage, data + ret, flex_array_size(buf, storage, data_len)); 937 938 /* 939 * At this point read_buffer is NULL or READ_BUFFER_DROP (if 940 * ffs_func_eps_disable has been called in the meanwhile). See comment 941 * in struct ffs_epfile for full read_buffer pointer synchronisation 942 * story. 943 */ 944 if (cmpxchg(&epfile->read_buffer, NULL, buf)) 945 kfree(buf); 946 947 return ret; 948 } 949 950 static ssize_t ffs_epfile_io(struct file *file, struct ffs_io_data *io_data) 951 { 952 struct ffs_epfile *epfile = file->private_data; 953 struct usb_request *req; 954 struct ffs_ep *ep; 955 char *data = NULL; 956 ssize_t ret, data_len = -EINVAL; 957 int halt; 958 959 /* Are we still active? */ 960 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 961 return -ENODEV; 962 963 /* Wait for endpoint to be enabled */ 964 ep = epfile->ep; 965 if (!ep) { 966 if (file->f_flags & O_NONBLOCK) 967 return -EAGAIN; 968 969 ret = wait_event_interruptible( 970 epfile->ffs->wait, (ep = epfile->ep)); 971 if (ret) 972 return -EINTR; 973 } 974 975 /* Do we halt? */ 976 halt = (!io_data->read == !epfile->in); 977 if (halt && epfile->isoc) 978 return -EINVAL; 979 980 /* We will be using request and read_buffer */ 981 ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK); 982 if (ret) 983 goto error; 984 985 /* Allocate & copy */ 986 if (!halt) { 987 struct usb_gadget *gadget; 988 989 /* 990 * Do we have buffered data from previous partial read? Check 991 * that for synchronous case only because we do not have 992 * facility to ‘wake up’ a pending asynchronous read and push 993 * buffered data to it which we would need to make things behave 994 * consistently. 995 */ 996 if (!io_data->aio && io_data->read) { 997 ret = __ffs_epfile_read_buffered(epfile, &io_data->data); 998 if (ret) 999 goto error_mutex; 1000 } 1001 1002 /* 1003 * if we _do_ wait above, the epfile->ffs->gadget might be NULL 1004 * before the waiting completes, so do not assign to 'gadget' 1005 * earlier 1006 */ 1007 gadget = epfile->ffs->gadget; 1008 1009 spin_lock_irq(&epfile->ffs->eps_lock); 1010 /* In the meantime, endpoint got disabled or changed. */ 1011 if (epfile->ep != ep) { 1012 ret = -ESHUTDOWN; 1013 goto error_lock; 1014 } 1015 data_len = iov_iter_count(&io_data->data); 1016 /* 1017 * Controller may require buffer size to be aligned to 1018 * maxpacketsize of an out endpoint. 1019 */ 1020 if (io_data->read) 1021 data_len = usb_ep_align_maybe(gadget, ep->ep, data_len); 1022 1023 io_data->use_sg = gadget->sg_supported && data_len > PAGE_SIZE; 1024 spin_unlock_irq(&epfile->ffs->eps_lock); 1025 1026 data = ffs_alloc_buffer(io_data, data_len); 1027 if (!data) { 1028 ret = -ENOMEM; 1029 goto error_mutex; 1030 } 1031 if (!io_data->read && 1032 !copy_from_iter_full(data, data_len, &io_data->data)) { 1033 ret = -EFAULT; 1034 goto error_mutex; 1035 } 1036 } 1037 1038 spin_lock_irq(&epfile->ffs->eps_lock); 1039 1040 if (epfile->ep != ep) { 1041 /* In the meantime, endpoint got disabled or changed. */ 1042 ret = -ESHUTDOWN; 1043 } else if (halt) { 1044 ret = usb_ep_set_halt(ep->ep); 1045 if (!ret) 1046 ret = -EBADMSG; 1047 } else if (data_len == -EINVAL) { 1048 /* 1049 * Sanity Check: even though data_len can't be used 1050 * uninitialized at the time I write this comment, some 1051 * compilers complain about this situation. 1052 * In order to keep the code clean from warnings, data_len is 1053 * being initialized to -EINVAL during its declaration, which 1054 * means we can't rely on compiler anymore to warn no future 1055 * changes won't result in data_len being used uninitialized. 1056 * For such reason, we're adding this redundant sanity check 1057 * here. 1058 */ 1059 WARN(1, "%s: data_len == -EINVAL\n", __func__); 1060 ret = -EINVAL; 1061 } else if (!io_data->aio) { 1062 bool interrupted = false; 1063 1064 req = ep->req; 1065 if (io_data->use_sg) { 1066 req->buf = NULL; 1067 req->sg = io_data->sgt.sgl; 1068 req->num_sgs = io_data->sgt.nents; 1069 } else { 1070 req->buf = data; 1071 req->num_sgs = 0; 1072 } 1073 req->length = data_len; 1074 1075 io_data->buf = data; 1076 1077 init_completion(&io_data->done); 1078 req->context = io_data; 1079 req->complete = ffs_epfile_io_complete; 1080 1081 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1082 if (ret < 0) 1083 goto error_lock; 1084 1085 spin_unlock_irq(&epfile->ffs->eps_lock); 1086 1087 if (wait_for_completion_interruptible(&io_data->done)) { 1088 spin_lock_irq(&epfile->ffs->eps_lock); 1089 if (epfile->ep != ep) { 1090 ret = -ESHUTDOWN; 1091 goto error_lock; 1092 } 1093 /* 1094 * To avoid race condition with ffs_epfile_io_complete, 1095 * dequeue the request first then check 1096 * status. usb_ep_dequeue API should guarantee no race 1097 * condition with req->complete callback. 1098 */ 1099 usb_ep_dequeue(ep->ep, req); 1100 spin_unlock_irq(&epfile->ffs->eps_lock); 1101 wait_for_completion(&io_data->done); 1102 interrupted = io_data->status < 0; 1103 } 1104 1105 if (interrupted) 1106 ret = -EINTR; 1107 else if (io_data->read && io_data->status > 0) 1108 ret = __ffs_epfile_read_data(epfile, data, io_data->status, 1109 &io_data->data); 1110 else 1111 ret = io_data->status; 1112 goto error_mutex; 1113 } else if (!(req = usb_ep_alloc_request(ep->ep, GFP_ATOMIC))) { 1114 ret = -ENOMEM; 1115 } else { 1116 if (io_data->use_sg) { 1117 req->buf = NULL; 1118 req->sg = io_data->sgt.sgl; 1119 req->num_sgs = io_data->sgt.nents; 1120 } else { 1121 req->buf = data; 1122 req->num_sgs = 0; 1123 } 1124 req->length = data_len; 1125 1126 io_data->buf = data; 1127 io_data->ep = ep->ep; 1128 io_data->req = req; 1129 io_data->ffs = epfile->ffs; 1130 1131 req->context = io_data; 1132 req->complete = ffs_epfile_async_io_complete; 1133 1134 ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC); 1135 if (ret) { 1136 io_data->req = NULL; 1137 usb_ep_free_request(ep->ep, req); 1138 goto error_lock; 1139 } 1140 1141 ret = -EIOCBQUEUED; 1142 /* 1143 * Do not kfree the buffer in this function. It will be freed 1144 * by ffs_user_copy_worker. 1145 */ 1146 data = NULL; 1147 } 1148 1149 error_lock: 1150 spin_unlock_irq(&epfile->ffs->eps_lock); 1151 error_mutex: 1152 mutex_unlock(&epfile->mutex); 1153 error: 1154 if (ret != -EIOCBQUEUED) /* don't free if there is iocb queued */ 1155 ffs_free_buffer(io_data); 1156 return ret; 1157 } 1158 1159 static int 1160 ffs_epfile_open(struct inode *inode, struct file *file) 1161 { 1162 struct ffs_epfile *epfile = inode->i_private; 1163 1164 ENTER(); 1165 1166 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1167 return -ENODEV; 1168 1169 file->private_data = epfile; 1170 ffs_data_opened(epfile->ffs); 1171 1172 return stream_open(inode, file); 1173 } 1174 1175 static int ffs_aio_cancel(struct kiocb *kiocb) 1176 { 1177 struct ffs_io_data *io_data = kiocb->private; 1178 struct ffs_epfile *epfile = kiocb->ki_filp->private_data; 1179 unsigned long flags; 1180 int value; 1181 1182 ENTER(); 1183 1184 spin_lock_irqsave(&epfile->ffs->eps_lock, flags); 1185 1186 if (io_data && io_data->ep && io_data->req) 1187 value = usb_ep_dequeue(io_data->ep, io_data->req); 1188 else 1189 value = -EINVAL; 1190 1191 spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags); 1192 1193 return value; 1194 } 1195 1196 static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) 1197 { 1198 struct ffs_io_data io_data, *p = &io_data; 1199 ssize_t res; 1200 1201 ENTER(); 1202 1203 if (!is_sync_kiocb(kiocb)) { 1204 p = kzalloc(sizeof(io_data), GFP_KERNEL); 1205 if (!p) 1206 return -ENOMEM; 1207 p->aio = true; 1208 } else { 1209 memset(p, 0, sizeof(*p)); 1210 p->aio = false; 1211 } 1212 1213 p->read = false; 1214 p->kiocb = kiocb; 1215 p->data = *from; 1216 p->mm = current->mm; 1217 1218 kiocb->private = p; 1219 1220 if (p->aio) 1221 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1222 1223 res = ffs_epfile_io(kiocb->ki_filp, p); 1224 if (res == -EIOCBQUEUED) 1225 return res; 1226 if (p->aio) 1227 kfree(p); 1228 else 1229 *from = p->data; 1230 return res; 1231 } 1232 1233 static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) 1234 { 1235 struct ffs_io_data io_data, *p = &io_data; 1236 ssize_t res; 1237 1238 ENTER(); 1239 1240 if (!is_sync_kiocb(kiocb)) { 1241 p = kzalloc(sizeof(io_data), GFP_KERNEL); 1242 if (!p) 1243 return -ENOMEM; 1244 p->aio = true; 1245 } else { 1246 memset(p, 0, sizeof(*p)); 1247 p->aio = false; 1248 } 1249 1250 p->read = true; 1251 p->kiocb = kiocb; 1252 if (p->aio) { 1253 p->to_free = dup_iter(&p->data, to, GFP_KERNEL); 1254 if (!p->to_free) { 1255 kfree(p); 1256 return -ENOMEM; 1257 } 1258 } else { 1259 p->data = *to; 1260 p->to_free = NULL; 1261 } 1262 p->mm = current->mm; 1263 1264 kiocb->private = p; 1265 1266 if (p->aio) 1267 kiocb_set_cancel_fn(kiocb, ffs_aio_cancel); 1268 1269 res = ffs_epfile_io(kiocb->ki_filp, p); 1270 if (res == -EIOCBQUEUED) 1271 return res; 1272 1273 if (p->aio) { 1274 kfree(p->to_free); 1275 kfree(p); 1276 } else { 1277 *to = p->data; 1278 } 1279 return res; 1280 } 1281 1282 static int 1283 ffs_epfile_release(struct inode *inode, struct file *file) 1284 { 1285 struct ffs_epfile *epfile = inode->i_private; 1286 1287 ENTER(); 1288 1289 __ffs_epfile_read_buffer_free(epfile); 1290 ffs_data_closed(epfile->ffs); 1291 1292 return 0; 1293 } 1294 1295 static long ffs_epfile_ioctl(struct file *file, unsigned code, 1296 unsigned long value) 1297 { 1298 struct ffs_epfile *epfile = file->private_data; 1299 struct ffs_ep *ep; 1300 int ret; 1301 1302 ENTER(); 1303 1304 if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) 1305 return -ENODEV; 1306 1307 /* Wait for endpoint to be enabled */ 1308 ep = epfile->ep; 1309 if (!ep) { 1310 if (file->f_flags & O_NONBLOCK) 1311 return -EAGAIN; 1312 1313 ret = wait_event_interruptible( 1314 epfile->ffs->wait, (ep = epfile->ep)); 1315 if (ret) 1316 return -EINTR; 1317 } 1318 1319 spin_lock_irq(&epfile->ffs->eps_lock); 1320 1321 /* In the meantime, endpoint got disabled or changed. */ 1322 if (epfile->ep != ep) { 1323 spin_unlock_irq(&epfile->ffs->eps_lock); 1324 return -ESHUTDOWN; 1325 } 1326 1327 switch (code) { 1328 case FUNCTIONFS_FIFO_STATUS: 1329 ret = usb_ep_fifo_status(epfile->ep->ep); 1330 break; 1331 case FUNCTIONFS_FIFO_FLUSH: 1332 usb_ep_fifo_flush(epfile->ep->ep); 1333 ret = 0; 1334 break; 1335 case FUNCTIONFS_CLEAR_HALT: 1336 ret = usb_ep_clear_halt(epfile->ep->ep); 1337 break; 1338 case FUNCTIONFS_ENDPOINT_REVMAP: 1339 ret = epfile->ep->num; 1340 break; 1341 case FUNCTIONFS_ENDPOINT_DESC: 1342 { 1343 int desc_idx; 1344 struct usb_endpoint_descriptor desc1, *desc; 1345 1346 switch (epfile->ffs->gadget->speed) { 1347 case USB_SPEED_SUPER: 1348 case USB_SPEED_SUPER_PLUS: 1349 desc_idx = 2; 1350 break; 1351 case USB_SPEED_HIGH: 1352 desc_idx = 1; 1353 break; 1354 default: 1355 desc_idx = 0; 1356 } 1357 1358 desc = epfile->ep->descs[desc_idx]; 1359 memcpy(&desc1, desc, desc->bLength); 1360 1361 spin_unlock_irq(&epfile->ffs->eps_lock); 1362 ret = copy_to_user((void __user *)value, &desc1, desc1.bLength); 1363 if (ret) 1364 ret = -EFAULT; 1365 return ret; 1366 } 1367 default: 1368 ret = -ENOTTY; 1369 } 1370 spin_unlock_irq(&epfile->ffs->eps_lock); 1371 1372 return ret; 1373 } 1374 1375 static const struct file_operations ffs_epfile_operations = { 1376 .llseek = no_llseek, 1377 1378 .open = ffs_epfile_open, 1379 .write_iter = ffs_epfile_write_iter, 1380 .read_iter = ffs_epfile_read_iter, 1381 .release = ffs_epfile_release, 1382 .unlocked_ioctl = ffs_epfile_ioctl, 1383 .compat_ioctl = compat_ptr_ioctl, 1384 }; 1385 1386 1387 /* File system and super block operations ***********************************/ 1388 1389 /* 1390 * Mounting the file system creates a controller file, used first for 1391 * function configuration then later for event monitoring. 1392 */ 1393 1394 static struct inode *__must_check 1395 ffs_sb_make_inode(struct super_block *sb, void *data, 1396 const struct file_operations *fops, 1397 const struct inode_operations *iops, 1398 struct ffs_file_perms *perms) 1399 { 1400 struct inode *inode; 1401 1402 ENTER(); 1403 1404 inode = new_inode(sb); 1405 1406 if (inode) { 1407 struct timespec64 ts = current_time(inode); 1408 1409 inode->i_ino = get_next_ino(); 1410 inode->i_mode = perms->mode; 1411 inode->i_uid = perms->uid; 1412 inode->i_gid = perms->gid; 1413 inode->i_atime = ts; 1414 inode->i_mtime = ts; 1415 inode->i_ctime = ts; 1416 inode->i_private = data; 1417 if (fops) 1418 inode->i_fop = fops; 1419 if (iops) 1420 inode->i_op = iops; 1421 } 1422 1423 return inode; 1424 } 1425 1426 /* Create "regular" file */ 1427 static struct dentry *ffs_sb_create_file(struct super_block *sb, 1428 const char *name, void *data, 1429 const struct file_operations *fops) 1430 { 1431 struct ffs_data *ffs = sb->s_fs_info; 1432 struct dentry *dentry; 1433 struct inode *inode; 1434 1435 ENTER(); 1436 1437 dentry = d_alloc_name(sb->s_root, name); 1438 if (!dentry) 1439 return NULL; 1440 1441 inode = ffs_sb_make_inode(sb, data, fops, NULL, &ffs->file_perms); 1442 if (!inode) { 1443 dput(dentry); 1444 return NULL; 1445 } 1446 1447 d_add(dentry, inode); 1448 return dentry; 1449 } 1450 1451 /* Super block */ 1452 static const struct super_operations ffs_sb_operations = { 1453 .statfs = simple_statfs, 1454 .drop_inode = generic_delete_inode, 1455 }; 1456 1457 struct ffs_sb_fill_data { 1458 struct ffs_file_perms perms; 1459 umode_t root_mode; 1460 const char *dev_name; 1461 bool no_disconnect; 1462 struct ffs_data *ffs_data; 1463 }; 1464 1465 static int ffs_sb_fill(struct super_block *sb, struct fs_context *fc) 1466 { 1467 struct ffs_sb_fill_data *data = fc->fs_private; 1468 struct inode *inode; 1469 struct ffs_data *ffs = data->ffs_data; 1470 1471 ENTER(); 1472 1473 ffs->sb = sb; 1474 data->ffs_data = NULL; 1475 sb->s_fs_info = ffs; 1476 sb->s_blocksize = PAGE_SIZE; 1477 sb->s_blocksize_bits = PAGE_SHIFT; 1478 sb->s_magic = FUNCTIONFS_MAGIC; 1479 sb->s_op = &ffs_sb_operations; 1480 sb->s_time_gran = 1; 1481 1482 /* Root inode */ 1483 data->perms.mode = data->root_mode; 1484 inode = ffs_sb_make_inode(sb, NULL, 1485 &simple_dir_operations, 1486 &simple_dir_inode_operations, 1487 &data->perms); 1488 sb->s_root = d_make_root(inode); 1489 if (!sb->s_root) 1490 return -ENOMEM; 1491 1492 /* EP0 file */ 1493 if (!ffs_sb_create_file(sb, "ep0", ffs, &ffs_ep0_operations)) 1494 return -ENOMEM; 1495 1496 return 0; 1497 } 1498 1499 enum { 1500 Opt_no_disconnect, 1501 Opt_rmode, 1502 Opt_fmode, 1503 Opt_mode, 1504 Opt_uid, 1505 Opt_gid, 1506 }; 1507 1508 static const struct fs_parameter_spec ffs_fs_fs_parameters[] = { 1509 fsparam_bool ("no_disconnect", Opt_no_disconnect), 1510 fsparam_u32 ("rmode", Opt_rmode), 1511 fsparam_u32 ("fmode", Opt_fmode), 1512 fsparam_u32 ("mode", Opt_mode), 1513 fsparam_u32 ("uid", Opt_uid), 1514 fsparam_u32 ("gid", Opt_gid), 1515 {} 1516 }; 1517 1518 static int ffs_fs_parse_param(struct fs_context *fc, struct fs_parameter *param) 1519 { 1520 struct ffs_sb_fill_data *data = fc->fs_private; 1521 struct fs_parse_result result; 1522 int opt; 1523 1524 ENTER(); 1525 1526 opt = fs_parse(fc, ffs_fs_fs_parameters, param, &result); 1527 if (opt < 0) 1528 return opt; 1529 1530 switch (opt) { 1531 case Opt_no_disconnect: 1532 data->no_disconnect = result.boolean; 1533 break; 1534 case Opt_rmode: 1535 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 1536 break; 1537 case Opt_fmode: 1538 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 1539 break; 1540 case Opt_mode: 1541 data->root_mode = (result.uint_32 & 0555) | S_IFDIR; 1542 data->perms.mode = (result.uint_32 & 0666) | S_IFREG; 1543 break; 1544 1545 case Opt_uid: 1546 data->perms.uid = make_kuid(current_user_ns(), result.uint_32); 1547 if (!uid_valid(data->perms.uid)) 1548 goto unmapped_value; 1549 break; 1550 case Opt_gid: 1551 data->perms.gid = make_kgid(current_user_ns(), result.uint_32); 1552 if (!gid_valid(data->perms.gid)) 1553 goto unmapped_value; 1554 break; 1555 1556 default: 1557 return -ENOPARAM; 1558 } 1559 1560 return 0; 1561 1562 unmapped_value: 1563 return invalf(fc, "%s: unmapped value: %u", param->key, result.uint_32); 1564 } 1565 1566 /* 1567 * Set up the superblock for a mount. 1568 */ 1569 static int ffs_fs_get_tree(struct fs_context *fc) 1570 { 1571 struct ffs_sb_fill_data *ctx = fc->fs_private; 1572 struct ffs_data *ffs; 1573 int ret; 1574 1575 ENTER(); 1576 1577 if (!fc->source) 1578 return invalf(fc, "No source specified"); 1579 1580 ffs = ffs_data_new(fc->source); 1581 if (!ffs) 1582 return -ENOMEM; 1583 ffs->file_perms = ctx->perms; 1584 ffs->no_disconnect = ctx->no_disconnect; 1585 1586 ffs->dev_name = kstrdup(fc->source, GFP_KERNEL); 1587 if (!ffs->dev_name) { 1588 ffs_data_put(ffs); 1589 return -ENOMEM; 1590 } 1591 1592 ret = ffs_acquire_dev(ffs->dev_name, ffs); 1593 if (ret) { 1594 ffs_data_put(ffs); 1595 return ret; 1596 } 1597 1598 ctx->ffs_data = ffs; 1599 return get_tree_nodev(fc, ffs_sb_fill); 1600 } 1601 1602 static void ffs_fs_free_fc(struct fs_context *fc) 1603 { 1604 struct ffs_sb_fill_data *ctx = fc->fs_private; 1605 1606 if (ctx) { 1607 if (ctx->ffs_data) { 1608 ffs_data_put(ctx->ffs_data); 1609 } 1610 1611 kfree(ctx); 1612 } 1613 } 1614 1615 static const struct fs_context_operations ffs_fs_context_ops = { 1616 .free = ffs_fs_free_fc, 1617 .parse_param = ffs_fs_parse_param, 1618 .get_tree = ffs_fs_get_tree, 1619 }; 1620 1621 static int ffs_fs_init_fs_context(struct fs_context *fc) 1622 { 1623 struct ffs_sb_fill_data *ctx; 1624 1625 ctx = kzalloc(sizeof(struct ffs_sb_fill_data), GFP_KERNEL); 1626 if (!ctx) 1627 return -ENOMEM; 1628 1629 ctx->perms.mode = S_IFREG | 0600; 1630 ctx->perms.uid = GLOBAL_ROOT_UID; 1631 ctx->perms.gid = GLOBAL_ROOT_GID; 1632 ctx->root_mode = S_IFDIR | 0500; 1633 ctx->no_disconnect = false; 1634 1635 fc->fs_private = ctx; 1636 fc->ops = &ffs_fs_context_ops; 1637 return 0; 1638 } 1639 1640 static void 1641 ffs_fs_kill_sb(struct super_block *sb) 1642 { 1643 ENTER(); 1644 1645 kill_litter_super(sb); 1646 if (sb->s_fs_info) 1647 ffs_data_closed(sb->s_fs_info); 1648 } 1649 1650 static struct file_system_type ffs_fs_type = { 1651 .owner = THIS_MODULE, 1652 .name = "functionfs", 1653 .init_fs_context = ffs_fs_init_fs_context, 1654 .parameters = ffs_fs_fs_parameters, 1655 .kill_sb = ffs_fs_kill_sb, 1656 }; 1657 MODULE_ALIAS_FS("functionfs"); 1658 1659 1660 /* Driver's main init/cleanup functions *************************************/ 1661 1662 static int functionfs_init(void) 1663 { 1664 int ret; 1665 1666 ENTER(); 1667 1668 ret = register_filesystem(&ffs_fs_type); 1669 if (!ret) 1670 pr_info("file system registered\n"); 1671 else 1672 pr_err("failed registering file system (%d)\n", ret); 1673 1674 return ret; 1675 } 1676 1677 static void functionfs_cleanup(void) 1678 { 1679 ENTER(); 1680 1681 pr_info("unloading\n"); 1682 unregister_filesystem(&ffs_fs_type); 1683 } 1684 1685 1686 /* ffs_data and ffs_function construction and destruction code **************/ 1687 1688 static void ffs_data_clear(struct ffs_data *ffs); 1689 static void ffs_data_reset(struct ffs_data *ffs); 1690 1691 static void ffs_data_get(struct ffs_data *ffs) 1692 { 1693 ENTER(); 1694 1695 refcount_inc(&ffs->ref); 1696 } 1697 1698 static void ffs_data_opened(struct ffs_data *ffs) 1699 { 1700 ENTER(); 1701 1702 refcount_inc(&ffs->ref); 1703 if (atomic_add_return(1, &ffs->opened) == 1 && 1704 ffs->state == FFS_DEACTIVATED) { 1705 ffs->state = FFS_CLOSING; 1706 ffs_data_reset(ffs); 1707 } 1708 } 1709 1710 static void ffs_data_put(struct ffs_data *ffs) 1711 { 1712 ENTER(); 1713 1714 if (refcount_dec_and_test(&ffs->ref)) { 1715 pr_info("%s(): freeing\n", __func__); 1716 ffs_data_clear(ffs); 1717 ffs_release_dev(ffs->private_data); 1718 BUG_ON(waitqueue_active(&ffs->ev.waitq) || 1719 swait_active(&ffs->ep0req_completion.wait) || 1720 waitqueue_active(&ffs->wait)); 1721 destroy_workqueue(ffs->io_completion_wq); 1722 kfree(ffs->dev_name); 1723 kfree(ffs); 1724 } 1725 } 1726 1727 static void ffs_data_closed(struct ffs_data *ffs) 1728 { 1729 struct ffs_epfile *epfiles; 1730 unsigned long flags; 1731 1732 ENTER(); 1733 1734 if (atomic_dec_and_test(&ffs->opened)) { 1735 if (ffs->no_disconnect) { 1736 ffs->state = FFS_DEACTIVATED; 1737 spin_lock_irqsave(&ffs->eps_lock, flags); 1738 epfiles = ffs->epfiles; 1739 ffs->epfiles = NULL; 1740 spin_unlock_irqrestore(&ffs->eps_lock, 1741 flags); 1742 1743 if (epfiles) 1744 ffs_epfiles_destroy(epfiles, 1745 ffs->eps_count); 1746 1747 if (ffs->setup_state == FFS_SETUP_PENDING) 1748 __ffs_ep0_stall(ffs); 1749 } else { 1750 ffs->state = FFS_CLOSING; 1751 ffs_data_reset(ffs); 1752 } 1753 } 1754 if (atomic_read(&ffs->opened) < 0) { 1755 ffs->state = FFS_CLOSING; 1756 ffs_data_reset(ffs); 1757 } 1758 1759 ffs_data_put(ffs); 1760 } 1761 1762 static struct ffs_data *ffs_data_new(const char *dev_name) 1763 { 1764 struct ffs_data *ffs = kzalloc(sizeof *ffs, GFP_KERNEL); 1765 if (!ffs) 1766 return NULL; 1767 1768 ENTER(); 1769 1770 ffs->io_completion_wq = alloc_ordered_workqueue("%s", 0, dev_name); 1771 if (!ffs->io_completion_wq) { 1772 kfree(ffs); 1773 return NULL; 1774 } 1775 1776 refcount_set(&ffs->ref, 1); 1777 atomic_set(&ffs->opened, 0); 1778 ffs->state = FFS_READ_DESCRIPTORS; 1779 mutex_init(&ffs->mutex); 1780 spin_lock_init(&ffs->eps_lock); 1781 init_waitqueue_head(&ffs->ev.waitq); 1782 init_waitqueue_head(&ffs->wait); 1783 init_completion(&ffs->ep0req_completion); 1784 1785 /* XXX REVISIT need to update it in some places, or do we? */ 1786 ffs->ev.can_stall = 1; 1787 1788 return ffs; 1789 } 1790 1791 static void ffs_data_clear(struct ffs_data *ffs) 1792 { 1793 struct ffs_epfile *epfiles; 1794 unsigned long flags; 1795 1796 ENTER(); 1797 1798 ffs_closed(ffs); 1799 1800 BUG_ON(ffs->gadget); 1801 1802 spin_lock_irqsave(&ffs->eps_lock, flags); 1803 epfiles = ffs->epfiles; 1804 ffs->epfiles = NULL; 1805 spin_unlock_irqrestore(&ffs->eps_lock, flags); 1806 1807 /* 1808 * potential race possible between ffs_func_eps_disable 1809 * & ffs_epfile_release therefore maintaining a local 1810 * copy of epfile will save us from use-after-free. 1811 */ 1812 if (epfiles) { 1813 ffs_epfiles_destroy(epfiles, ffs->eps_count); 1814 ffs->epfiles = NULL; 1815 } 1816 1817 if (ffs->ffs_eventfd) { 1818 eventfd_ctx_put(ffs->ffs_eventfd); 1819 ffs->ffs_eventfd = NULL; 1820 } 1821 1822 kfree(ffs->raw_descs_data); 1823 kfree(ffs->raw_strings); 1824 kfree(ffs->stringtabs); 1825 } 1826 1827 static void ffs_data_reset(struct ffs_data *ffs) 1828 { 1829 ENTER(); 1830 1831 ffs_data_clear(ffs); 1832 1833 ffs->raw_descs_data = NULL; 1834 ffs->raw_descs = NULL; 1835 ffs->raw_strings = NULL; 1836 ffs->stringtabs = NULL; 1837 1838 ffs->raw_descs_length = 0; 1839 ffs->fs_descs_count = 0; 1840 ffs->hs_descs_count = 0; 1841 ffs->ss_descs_count = 0; 1842 1843 ffs->strings_count = 0; 1844 ffs->interfaces_count = 0; 1845 ffs->eps_count = 0; 1846 1847 ffs->ev.count = 0; 1848 1849 ffs->state = FFS_READ_DESCRIPTORS; 1850 ffs->setup_state = FFS_NO_SETUP; 1851 ffs->flags = 0; 1852 1853 ffs->ms_os_descs_ext_prop_count = 0; 1854 ffs->ms_os_descs_ext_prop_name_len = 0; 1855 ffs->ms_os_descs_ext_prop_data_len = 0; 1856 } 1857 1858 1859 static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev) 1860 { 1861 struct usb_gadget_strings **lang; 1862 int first_id; 1863 1864 ENTER(); 1865 1866 if (WARN_ON(ffs->state != FFS_ACTIVE 1867 || test_and_set_bit(FFS_FL_BOUND, &ffs->flags))) 1868 return -EBADFD; 1869 1870 first_id = usb_string_ids_n(cdev, ffs->strings_count); 1871 if (first_id < 0) 1872 return first_id; 1873 1874 ffs->ep0req = usb_ep_alloc_request(cdev->gadget->ep0, GFP_KERNEL); 1875 if (!ffs->ep0req) 1876 return -ENOMEM; 1877 ffs->ep0req->complete = ffs_ep0_complete; 1878 ffs->ep0req->context = ffs; 1879 1880 lang = ffs->stringtabs; 1881 if (lang) { 1882 for (; *lang; ++lang) { 1883 struct usb_string *str = (*lang)->strings; 1884 int id = first_id; 1885 for (; str->s; ++id, ++str) 1886 str->id = id; 1887 } 1888 } 1889 1890 ffs->gadget = cdev->gadget; 1891 ffs_data_get(ffs); 1892 return 0; 1893 } 1894 1895 static void functionfs_unbind(struct ffs_data *ffs) 1896 { 1897 ENTER(); 1898 1899 if (!WARN_ON(!ffs->gadget)) { 1900 /* dequeue before freeing ep0req */ 1901 usb_ep_dequeue(ffs->gadget->ep0, ffs->ep0req); 1902 mutex_lock(&ffs->mutex); 1903 usb_ep_free_request(ffs->gadget->ep0, ffs->ep0req); 1904 ffs->ep0req = NULL; 1905 ffs->gadget = NULL; 1906 clear_bit(FFS_FL_BOUND, &ffs->flags); 1907 mutex_unlock(&ffs->mutex); 1908 ffs_data_put(ffs); 1909 } 1910 } 1911 1912 static int ffs_epfiles_create(struct ffs_data *ffs) 1913 { 1914 struct ffs_epfile *epfile, *epfiles; 1915 unsigned i, count; 1916 1917 ENTER(); 1918 1919 count = ffs->eps_count; 1920 epfiles = kcalloc(count, sizeof(*epfiles), GFP_KERNEL); 1921 if (!epfiles) 1922 return -ENOMEM; 1923 1924 epfile = epfiles; 1925 for (i = 1; i <= count; ++i, ++epfile) { 1926 epfile->ffs = ffs; 1927 mutex_init(&epfile->mutex); 1928 if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 1929 sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]); 1930 else 1931 sprintf(epfile->name, "ep%u", i); 1932 epfile->dentry = ffs_sb_create_file(ffs->sb, epfile->name, 1933 epfile, 1934 &ffs_epfile_operations); 1935 if (!epfile->dentry) { 1936 ffs_epfiles_destroy(epfiles, i - 1); 1937 return -ENOMEM; 1938 } 1939 } 1940 1941 ffs->epfiles = epfiles; 1942 return 0; 1943 } 1944 1945 static void ffs_epfiles_destroy(struct ffs_epfile *epfiles, unsigned count) 1946 { 1947 struct ffs_epfile *epfile = epfiles; 1948 1949 ENTER(); 1950 1951 for (; count; --count, ++epfile) { 1952 BUG_ON(mutex_is_locked(&epfile->mutex)); 1953 if (epfile->dentry) { 1954 d_delete(epfile->dentry); 1955 dput(epfile->dentry); 1956 epfile->dentry = NULL; 1957 } 1958 } 1959 1960 kfree(epfiles); 1961 } 1962 1963 static void ffs_func_eps_disable(struct ffs_function *func) 1964 { 1965 struct ffs_ep *ep; 1966 struct ffs_epfile *epfile; 1967 unsigned short count; 1968 unsigned long flags; 1969 1970 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1971 count = func->ffs->eps_count; 1972 epfile = func->ffs->epfiles; 1973 ep = func->eps; 1974 while (count--) { 1975 /* pending requests get nuked */ 1976 if (ep->ep) 1977 usb_ep_disable(ep->ep); 1978 ++ep; 1979 1980 if (epfile) { 1981 epfile->ep = NULL; 1982 __ffs_epfile_read_buffer_free(epfile); 1983 ++epfile; 1984 } 1985 } 1986 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 1987 } 1988 1989 static int ffs_func_eps_enable(struct ffs_function *func) 1990 { 1991 struct ffs_data *ffs; 1992 struct ffs_ep *ep; 1993 struct ffs_epfile *epfile; 1994 unsigned short count; 1995 unsigned long flags; 1996 int ret = 0; 1997 1998 spin_lock_irqsave(&func->ffs->eps_lock, flags); 1999 ffs = func->ffs; 2000 ep = func->eps; 2001 epfile = ffs->epfiles; 2002 count = ffs->eps_count; 2003 while(count--) { 2004 ep->ep->driver_data = ep; 2005 2006 ret = config_ep_by_speed(func->gadget, &func->function, ep->ep); 2007 if (ret) { 2008 pr_err("%s: config_ep_by_speed(%s) returned %d\n", 2009 __func__, ep->ep->name, ret); 2010 break; 2011 } 2012 2013 ret = usb_ep_enable(ep->ep); 2014 if (!ret) { 2015 epfile->ep = ep; 2016 epfile->in = usb_endpoint_dir_in(ep->ep->desc); 2017 epfile->isoc = usb_endpoint_xfer_isoc(ep->ep->desc); 2018 } else { 2019 break; 2020 } 2021 2022 ++ep; 2023 ++epfile; 2024 } 2025 2026 wake_up_interruptible(&ffs->wait); 2027 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 2028 2029 return ret; 2030 } 2031 2032 2033 /* Parsing and building descriptors and strings *****************************/ 2034 2035 /* 2036 * This validates if data pointed by data is a valid USB descriptor as 2037 * well as record how many interfaces, endpoints and strings are 2038 * required by given configuration. Returns address after the 2039 * descriptor or NULL if data is invalid. 2040 */ 2041 2042 enum ffs_entity_type { 2043 FFS_DESCRIPTOR, FFS_INTERFACE, FFS_STRING, FFS_ENDPOINT 2044 }; 2045 2046 enum ffs_os_desc_type { 2047 FFS_OS_DESC, FFS_OS_DESC_EXT_COMPAT, FFS_OS_DESC_EXT_PROP 2048 }; 2049 2050 typedef int (*ffs_entity_callback)(enum ffs_entity_type entity, 2051 u8 *valuep, 2052 struct usb_descriptor_header *desc, 2053 void *priv); 2054 2055 typedef int (*ffs_os_desc_callback)(enum ffs_os_desc_type entity, 2056 struct usb_os_desc_header *h, void *data, 2057 unsigned len, void *priv); 2058 2059 static int __must_check ffs_do_single_desc(char *data, unsigned len, 2060 ffs_entity_callback entity, 2061 void *priv, int *current_class) 2062 { 2063 struct usb_descriptor_header *_ds = (void *)data; 2064 u8 length; 2065 int ret; 2066 2067 ENTER(); 2068 2069 /* At least two bytes are required: length and type */ 2070 if (len < 2) { 2071 pr_vdebug("descriptor too short\n"); 2072 return -EINVAL; 2073 } 2074 2075 /* If we have at least as many bytes as the descriptor takes? */ 2076 length = _ds->bLength; 2077 if (len < length) { 2078 pr_vdebug("descriptor longer then available data\n"); 2079 return -EINVAL; 2080 } 2081 2082 #define __entity_check_INTERFACE(val) 1 2083 #define __entity_check_STRING(val) (val) 2084 #define __entity_check_ENDPOINT(val) ((val) & USB_ENDPOINT_NUMBER_MASK) 2085 #define __entity(type, val) do { \ 2086 pr_vdebug("entity " #type "(%02x)\n", (val)); \ 2087 if (!__entity_check_ ##type(val)) { \ 2088 pr_vdebug("invalid entity's value\n"); \ 2089 return -EINVAL; \ 2090 } \ 2091 ret = entity(FFS_ ##type, &val, _ds, priv); \ 2092 if (ret < 0) { \ 2093 pr_debug("entity " #type "(%02x); ret = %d\n", \ 2094 (val), ret); \ 2095 return ret; \ 2096 } \ 2097 } while (0) 2098 2099 /* Parse descriptor depending on type. */ 2100 switch (_ds->bDescriptorType) { 2101 case USB_DT_DEVICE: 2102 case USB_DT_CONFIG: 2103 case USB_DT_STRING: 2104 case USB_DT_DEVICE_QUALIFIER: 2105 /* function can't have any of those */ 2106 pr_vdebug("descriptor reserved for gadget: %d\n", 2107 _ds->bDescriptorType); 2108 return -EINVAL; 2109 2110 case USB_DT_INTERFACE: { 2111 struct usb_interface_descriptor *ds = (void *)_ds; 2112 pr_vdebug("interface descriptor\n"); 2113 if (length != sizeof *ds) 2114 goto inv_length; 2115 2116 __entity(INTERFACE, ds->bInterfaceNumber); 2117 if (ds->iInterface) 2118 __entity(STRING, ds->iInterface); 2119 *current_class = ds->bInterfaceClass; 2120 } 2121 break; 2122 2123 case USB_DT_ENDPOINT: { 2124 struct usb_endpoint_descriptor *ds = (void *)_ds; 2125 pr_vdebug("endpoint descriptor\n"); 2126 if (length != USB_DT_ENDPOINT_SIZE && 2127 length != USB_DT_ENDPOINT_AUDIO_SIZE) 2128 goto inv_length; 2129 __entity(ENDPOINT, ds->bEndpointAddress); 2130 } 2131 break; 2132 2133 case USB_TYPE_CLASS | 0x01: 2134 if (*current_class == USB_INTERFACE_CLASS_HID) { 2135 pr_vdebug("hid descriptor\n"); 2136 if (length != sizeof(struct hid_descriptor)) 2137 goto inv_length; 2138 break; 2139 } else if (*current_class == USB_INTERFACE_CLASS_CCID) { 2140 pr_vdebug("ccid descriptor\n"); 2141 if (length != sizeof(struct ccid_descriptor)) 2142 goto inv_length; 2143 break; 2144 } else { 2145 pr_vdebug("unknown descriptor: %d for class %d\n", 2146 _ds->bDescriptorType, *current_class); 2147 return -EINVAL; 2148 } 2149 2150 case USB_DT_OTG: 2151 if (length != sizeof(struct usb_otg_descriptor)) 2152 goto inv_length; 2153 break; 2154 2155 case USB_DT_INTERFACE_ASSOCIATION: { 2156 struct usb_interface_assoc_descriptor *ds = (void *)_ds; 2157 pr_vdebug("interface association descriptor\n"); 2158 if (length != sizeof *ds) 2159 goto inv_length; 2160 if (ds->iFunction) 2161 __entity(STRING, ds->iFunction); 2162 } 2163 break; 2164 2165 case USB_DT_SS_ENDPOINT_COMP: 2166 pr_vdebug("EP SS companion descriptor\n"); 2167 if (length != sizeof(struct usb_ss_ep_comp_descriptor)) 2168 goto inv_length; 2169 break; 2170 2171 case USB_DT_OTHER_SPEED_CONFIG: 2172 case USB_DT_INTERFACE_POWER: 2173 case USB_DT_DEBUG: 2174 case USB_DT_SECURITY: 2175 case USB_DT_CS_RADIO_CONTROL: 2176 /* TODO */ 2177 pr_vdebug("unimplemented descriptor: %d\n", _ds->bDescriptorType); 2178 return -EINVAL; 2179 2180 default: 2181 /* We should never be here */ 2182 pr_vdebug("unknown descriptor: %d\n", _ds->bDescriptorType); 2183 return -EINVAL; 2184 2185 inv_length: 2186 pr_vdebug("invalid length: %d (descriptor %d)\n", 2187 _ds->bLength, _ds->bDescriptorType); 2188 return -EINVAL; 2189 } 2190 2191 #undef __entity 2192 #undef __entity_check_DESCRIPTOR 2193 #undef __entity_check_INTERFACE 2194 #undef __entity_check_STRING 2195 #undef __entity_check_ENDPOINT 2196 2197 return length; 2198 } 2199 2200 static int __must_check ffs_do_descs(unsigned count, char *data, unsigned len, 2201 ffs_entity_callback entity, void *priv) 2202 { 2203 const unsigned _len = len; 2204 unsigned long num = 0; 2205 int current_class = -1; 2206 2207 ENTER(); 2208 2209 for (;;) { 2210 int ret; 2211 2212 if (num == count) 2213 data = NULL; 2214 2215 /* Record "descriptor" entity */ 2216 ret = entity(FFS_DESCRIPTOR, (u8 *)num, (void *)data, priv); 2217 if (ret < 0) { 2218 pr_debug("entity DESCRIPTOR(%02lx); ret = %d\n", 2219 num, ret); 2220 return ret; 2221 } 2222 2223 if (!data) 2224 return _len - len; 2225 2226 ret = ffs_do_single_desc(data, len, entity, priv, 2227 ¤t_class); 2228 if (ret < 0) { 2229 pr_debug("%s returns %d\n", __func__, ret); 2230 return ret; 2231 } 2232 2233 len -= ret; 2234 data += ret; 2235 ++num; 2236 } 2237 } 2238 2239 static int __ffs_data_do_entity(enum ffs_entity_type type, 2240 u8 *valuep, struct usb_descriptor_header *desc, 2241 void *priv) 2242 { 2243 struct ffs_desc_helper *helper = priv; 2244 struct usb_endpoint_descriptor *d; 2245 2246 ENTER(); 2247 2248 switch (type) { 2249 case FFS_DESCRIPTOR: 2250 break; 2251 2252 case FFS_INTERFACE: 2253 /* 2254 * Interfaces are indexed from zero so if we 2255 * encountered interface "n" then there are at least 2256 * "n+1" interfaces. 2257 */ 2258 if (*valuep >= helper->interfaces_count) 2259 helper->interfaces_count = *valuep + 1; 2260 break; 2261 2262 case FFS_STRING: 2263 /* 2264 * Strings are indexed from 1 (0 is reserved 2265 * for languages list) 2266 */ 2267 if (*valuep > helper->ffs->strings_count) 2268 helper->ffs->strings_count = *valuep; 2269 break; 2270 2271 case FFS_ENDPOINT: 2272 d = (void *)desc; 2273 helper->eps_count++; 2274 if (helper->eps_count >= FFS_MAX_EPS_COUNT) 2275 return -EINVAL; 2276 /* Check if descriptors for any speed were already parsed */ 2277 if (!helper->ffs->eps_count && !helper->ffs->interfaces_count) 2278 helper->ffs->eps_addrmap[helper->eps_count] = 2279 d->bEndpointAddress; 2280 else if (helper->ffs->eps_addrmap[helper->eps_count] != 2281 d->bEndpointAddress) 2282 return -EINVAL; 2283 break; 2284 } 2285 2286 return 0; 2287 } 2288 2289 static int __ffs_do_os_desc_header(enum ffs_os_desc_type *next_type, 2290 struct usb_os_desc_header *desc) 2291 { 2292 u16 bcd_version = le16_to_cpu(desc->bcdVersion); 2293 u16 w_index = le16_to_cpu(desc->wIndex); 2294 2295 if (bcd_version != 1) { 2296 pr_vdebug("unsupported os descriptors version: %d", 2297 bcd_version); 2298 return -EINVAL; 2299 } 2300 switch (w_index) { 2301 case 0x4: 2302 *next_type = FFS_OS_DESC_EXT_COMPAT; 2303 break; 2304 case 0x5: 2305 *next_type = FFS_OS_DESC_EXT_PROP; 2306 break; 2307 default: 2308 pr_vdebug("unsupported os descriptor type: %d", w_index); 2309 return -EINVAL; 2310 } 2311 2312 return sizeof(*desc); 2313 } 2314 2315 /* 2316 * Process all extended compatibility/extended property descriptors 2317 * of a feature descriptor 2318 */ 2319 static int __must_check ffs_do_single_os_desc(char *data, unsigned len, 2320 enum ffs_os_desc_type type, 2321 u16 feature_count, 2322 ffs_os_desc_callback entity, 2323 void *priv, 2324 struct usb_os_desc_header *h) 2325 { 2326 int ret; 2327 const unsigned _len = len; 2328 2329 ENTER(); 2330 2331 /* loop over all ext compat/ext prop descriptors */ 2332 while (feature_count--) { 2333 ret = entity(type, h, data, len, priv); 2334 if (ret < 0) { 2335 pr_debug("bad OS descriptor, type: %d\n", type); 2336 return ret; 2337 } 2338 data += ret; 2339 len -= ret; 2340 } 2341 return _len - len; 2342 } 2343 2344 /* Process a number of complete Feature Descriptors (Ext Compat or Ext Prop) */ 2345 static int __must_check ffs_do_os_descs(unsigned count, 2346 char *data, unsigned len, 2347 ffs_os_desc_callback entity, void *priv) 2348 { 2349 const unsigned _len = len; 2350 unsigned long num = 0; 2351 2352 ENTER(); 2353 2354 for (num = 0; num < count; ++num) { 2355 int ret; 2356 enum ffs_os_desc_type type; 2357 u16 feature_count; 2358 struct usb_os_desc_header *desc = (void *)data; 2359 2360 if (len < sizeof(*desc)) 2361 return -EINVAL; 2362 2363 /* 2364 * Record "descriptor" entity. 2365 * Process dwLength, bcdVersion, wIndex, get b/wCount. 2366 * Move the data pointer to the beginning of extended 2367 * compatibilities proper or extended properties proper 2368 * portions of the data 2369 */ 2370 if (le32_to_cpu(desc->dwLength) > len) 2371 return -EINVAL; 2372 2373 ret = __ffs_do_os_desc_header(&type, desc); 2374 if (ret < 0) { 2375 pr_debug("entity OS_DESCRIPTOR(%02lx); ret = %d\n", 2376 num, ret); 2377 return ret; 2378 } 2379 /* 2380 * 16-bit hex "?? 00" Little Endian looks like 8-bit hex "??" 2381 */ 2382 feature_count = le16_to_cpu(desc->wCount); 2383 if (type == FFS_OS_DESC_EXT_COMPAT && 2384 (feature_count > 255 || desc->Reserved)) 2385 return -EINVAL; 2386 len -= ret; 2387 data += ret; 2388 2389 /* 2390 * Process all function/property descriptors 2391 * of this Feature Descriptor 2392 */ 2393 ret = ffs_do_single_os_desc(data, len, type, 2394 feature_count, entity, priv, desc); 2395 if (ret < 0) { 2396 pr_debug("%s returns %d\n", __func__, ret); 2397 return ret; 2398 } 2399 2400 len -= ret; 2401 data += ret; 2402 } 2403 return _len - len; 2404 } 2405 2406 /* 2407 * Validate contents of the buffer from userspace related to OS descriptors. 2408 */ 2409 static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, 2410 struct usb_os_desc_header *h, void *data, 2411 unsigned len, void *priv) 2412 { 2413 struct ffs_data *ffs = priv; 2414 u8 length; 2415 2416 ENTER(); 2417 2418 switch (type) { 2419 case FFS_OS_DESC_EXT_COMPAT: { 2420 struct usb_ext_compat_desc *d = data; 2421 int i; 2422 2423 if (len < sizeof(*d) || 2424 d->bFirstInterfaceNumber >= ffs->interfaces_count) 2425 return -EINVAL; 2426 if (d->Reserved1 != 1) { 2427 /* 2428 * According to the spec, Reserved1 must be set to 1 2429 * but older kernels incorrectly rejected non-zero 2430 * values. We fix it here to avoid returning EINVAL 2431 * in response to values we used to accept. 2432 */ 2433 pr_debug("usb_ext_compat_desc::Reserved1 forced to 1\n"); 2434 d->Reserved1 = 1; 2435 } 2436 for (i = 0; i < ARRAY_SIZE(d->Reserved2); ++i) 2437 if (d->Reserved2[i]) 2438 return -EINVAL; 2439 2440 length = sizeof(struct usb_ext_compat_desc); 2441 } 2442 break; 2443 case FFS_OS_DESC_EXT_PROP: { 2444 struct usb_ext_prop_desc *d = data; 2445 u32 type, pdl; 2446 u16 pnl; 2447 2448 if (len < sizeof(*d) || h->interface >= ffs->interfaces_count) 2449 return -EINVAL; 2450 length = le32_to_cpu(d->dwSize); 2451 if (len < length) 2452 return -EINVAL; 2453 type = le32_to_cpu(d->dwPropertyDataType); 2454 if (type < USB_EXT_PROP_UNICODE || 2455 type > USB_EXT_PROP_UNICODE_MULTI) { 2456 pr_vdebug("unsupported os descriptor property type: %d", 2457 type); 2458 return -EINVAL; 2459 } 2460 pnl = le16_to_cpu(d->wPropertyNameLength); 2461 if (length < 14 + pnl) { 2462 pr_vdebug("invalid os descriptor length: %d pnl:%d (descriptor %d)\n", 2463 length, pnl, type); 2464 return -EINVAL; 2465 } 2466 pdl = le32_to_cpu(*(__le32 *)((u8 *)data + 10 + pnl)); 2467 if (length != 14 + pnl + pdl) { 2468 pr_vdebug("invalid os descriptor length: %d pnl:%d pdl:%d (descriptor %d)\n", 2469 length, pnl, pdl, type); 2470 return -EINVAL; 2471 } 2472 ++ffs->ms_os_descs_ext_prop_count; 2473 /* property name reported to the host as "WCHAR"s */ 2474 ffs->ms_os_descs_ext_prop_name_len += pnl * 2; 2475 ffs->ms_os_descs_ext_prop_data_len += pdl; 2476 } 2477 break; 2478 default: 2479 pr_vdebug("unknown descriptor: %d\n", type); 2480 return -EINVAL; 2481 } 2482 return length; 2483 } 2484 2485 static int __ffs_data_got_descs(struct ffs_data *ffs, 2486 char *const _data, size_t len) 2487 { 2488 char *data = _data, *raw_descs; 2489 unsigned os_descs_count = 0, counts[3], flags; 2490 int ret = -EINVAL, i; 2491 struct ffs_desc_helper helper; 2492 2493 ENTER(); 2494 2495 if (get_unaligned_le32(data + 4) != len) 2496 goto error; 2497 2498 switch (get_unaligned_le32(data)) { 2499 case FUNCTIONFS_DESCRIPTORS_MAGIC: 2500 flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC; 2501 data += 8; 2502 len -= 8; 2503 break; 2504 case FUNCTIONFS_DESCRIPTORS_MAGIC_V2: 2505 flags = get_unaligned_le32(data + 8); 2506 ffs->user_flags = flags; 2507 if (flags & ~(FUNCTIONFS_HAS_FS_DESC | 2508 FUNCTIONFS_HAS_HS_DESC | 2509 FUNCTIONFS_HAS_SS_DESC | 2510 FUNCTIONFS_HAS_MS_OS_DESC | 2511 FUNCTIONFS_VIRTUAL_ADDR | 2512 FUNCTIONFS_EVENTFD | 2513 FUNCTIONFS_ALL_CTRL_RECIP | 2514 FUNCTIONFS_CONFIG0_SETUP)) { 2515 ret = -ENOSYS; 2516 goto error; 2517 } 2518 data += 12; 2519 len -= 12; 2520 break; 2521 default: 2522 goto error; 2523 } 2524 2525 if (flags & FUNCTIONFS_EVENTFD) { 2526 if (len < 4) 2527 goto error; 2528 ffs->ffs_eventfd = 2529 eventfd_ctx_fdget((int)get_unaligned_le32(data)); 2530 if (IS_ERR(ffs->ffs_eventfd)) { 2531 ret = PTR_ERR(ffs->ffs_eventfd); 2532 ffs->ffs_eventfd = NULL; 2533 goto error; 2534 } 2535 data += 4; 2536 len -= 4; 2537 } 2538 2539 /* Read fs_count, hs_count and ss_count (if present) */ 2540 for (i = 0; i < 3; ++i) { 2541 if (!(flags & (1 << i))) { 2542 counts[i] = 0; 2543 } else if (len < 4) { 2544 goto error; 2545 } else { 2546 counts[i] = get_unaligned_le32(data); 2547 data += 4; 2548 len -= 4; 2549 } 2550 } 2551 if (flags & (1 << i)) { 2552 if (len < 4) { 2553 goto error; 2554 } 2555 os_descs_count = get_unaligned_le32(data); 2556 data += 4; 2557 len -= 4; 2558 } 2559 2560 /* Read descriptors */ 2561 raw_descs = data; 2562 helper.ffs = ffs; 2563 for (i = 0; i < 3; ++i) { 2564 if (!counts[i]) 2565 continue; 2566 helper.interfaces_count = 0; 2567 helper.eps_count = 0; 2568 ret = ffs_do_descs(counts[i], data, len, 2569 __ffs_data_do_entity, &helper); 2570 if (ret < 0) 2571 goto error; 2572 if (!ffs->eps_count && !ffs->interfaces_count) { 2573 ffs->eps_count = helper.eps_count; 2574 ffs->interfaces_count = helper.interfaces_count; 2575 } else { 2576 if (ffs->eps_count != helper.eps_count) { 2577 ret = -EINVAL; 2578 goto error; 2579 } 2580 if (ffs->interfaces_count != helper.interfaces_count) { 2581 ret = -EINVAL; 2582 goto error; 2583 } 2584 } 2585 data += ret; 2586 len -= ret; 2587 } 2588 if (os_descs_count) { 2589 ret = ffs_do_os_descs(os_descs_count, data, len, 2590 __ffs_data_do_os_desc, ffs); 2591 if (ret < 0) 2592 goto error; 2593 data += ret; 2594 len -= ret; 2595 } 2596 2597 if (raw_descs == data || len) { 2598 ret = -EINVAL; 2599 goto error; 2600 } 2601 2602 ffs->raw_descs_data = _data; 2603 ffs->raw_descs = raw_descs; 2604 ffs->raw_descs_length = data - raw_descs; 2605 ffs->fs_descs_count = counts[0]; 2606 ffs->hs_descs_count = counts[1]; 2607 ffs->ss_descs_count = counts[2]; 2608 ffs->ms_os_descs_count = os_descs_count; 2609 2610 return 0; 2611 2612 error: 2613 kfree(_data); 2614 return ret; 2615 } 2616 2617 static int __ffs_data_got_strings(struct ffs_data *ffs, 2618 char *const _data, size_t len) 2619 { 2620 u32 str_count, needed_count, lang_count; 2621 struct usb_gadget_strings **stringtabs, *t; 2622 const char *data = _data; 2623 struct usb_string *s; 2624 2625 ENTER(); 2626 2627 if (len < 16 || 2628 get_unaligned_le32(data) != FUNCTIONFS_STRINGS_MAGIC || 2629 get_unaligned_le32(data + 4) != len) 2630 goto error; 2631 str_count = get_unaligned_le32(data + 8); 2632 lang_count = get_unaligned_le32(data + 12); 2633 2634 /* if one is zero the other must be zero */ 2635 if (!str_count != !lang_count) 2636 goto error; 2637 2638 /* Do we have at least as many strings as descriptors need? */ 2639 needed_count = ffs->strings_count; 2640 if (str_count < needed_count) 2641 goto error; 2642 2643 /* 2644 * If we don't need any strings just return and free all 2645 * memory. 2646 */ 2647 if (!needed_count) { 2648 kfree(_data); 2649 return 0; 2650 } 2651 2652 /* Allocate everything in one chunk so there's less maintenance. */ 2653 { 2654 unsigned i = 0; 2655 vla_group(d); 2656 vla_item(d, struct usb_gadget_strings *, stringtabs, 2657 size_add(lang_count, 1)); 2658 vla_item(d, struct usb_gadget_strings, stringtab, lang_count); 2659 vla_item(d, struct usb_string, strings, 2660 size_mul(lang_count, (needed_count + 1))); 2661 2662 char *vlabuf = kmalloc(vla_group_size(d), GFP_KERNEL); 2663 2664 if (!vlabuf) { 2665 kfree(_data); 2666 return -ENOMEM; 2667 } 2668 2669 /* Initialize the VLA pointers */ 2670 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2671 t = vla_ptr(vlabuf, d, stringtab); 2672 i = lang_count; 2673 do { 2674 *stringtabs++ = t++; 2675 } while (--i); 2676 *stringtabs = NULL; 2677 2678 /* stringtabs = vlabuf = d_stringtabs for later kfree */ 2679 stringtabs = vla_ptr(vlabuf, d, stringtabs); 2680 t = vla_ptr(vlabuf, d, stringtab); 2681 s = vla_ptr(vlabuf, d, strings); 2682 } 2683 2684 /* For each language */ 2685 data += 16; 2686 len -= 16; 2687 2688 do { /* lang_count > 0 so we can use do-while */ 2689 unsigned needed = needed_count; 2690 u32 str_per_lang = str_count; 2691 2692 if (len < 3) 2693 goto error_free; 2694 t->language = get_unaligned_le16(data); 2695 t->strings = s; 2696 ++t; 2697 2698 data += 2; 2699 len -= 2; 2700 2701 /* For each string */ 2702 do { /* str_count > 0 so we can use do-while */ 2703 size_t length = strnlen(data, len); 2704 2705 if (length == len) 2706 goto error_free; 2707 2708 /* 2709 * User may provide more strings then we need, 2710 * if that's the case we simply ignore the 2711 * rest 2712 */ 2713 if (needed) { 2714 /* 2715 * s->id will be set while adding 2716 * function to configuration so for 2717 * now just leave garbage here. 2718 */ 2719 s->s = data; 2720 --needed; 2721 ++s; 2722 } 2723 2724 data += length + 1; 2725 len -= length + 1; 2726 } while (--str_per_lang); 2727 2728 s->id = 0; /* terminator */ 2729 s->s = NULL; 2730 ++s; 2731 2732 } while (--lang_count); 2733 2734 /* Some garbage left? */ 2735 if (len) 2736 goto error_free; 2737 2738 /* Done! */ 2739 ffs->stringtabs = stringtabs; 2740 ffs->raw_strings = _data; 2741 2742 return 0; 2743 2744 error_free: 2745 kfree(stringtabs); 2746 error: 2747 kfree(_data); 2748 return -EINVAL; 2749 } 2750 2751 2752 /* Events handling and management *******************************************/ 2753 2754 static void __ffs_event_add(struct ffs_data *ffs, 2755 enum usb_functionfs_event_type type) 2756 { 2757 enum usb_functionfs_event_type rem_type1, rem_type2 = type; 2758 int neg = 0; 2759 2760 /* 2761 * Abort any unhandled setup 2762 * 2763 * We do not need to worry about some cmpxchg() changing value 2764 * of ffs->setup_state without holding the lock because when 2765 * state is FFS_SETUP_PENDING cmpxchg() in several places in 2766 * the source does nothing. 2767 */ 2768 if (ffs->setup_state == FFS_SETUP_PENDING) 2769 ffs->setup_state = FFS_SETUP_CANCELLED; 2770 2771 /* 2772 * Logic of this function guarantees that there are at most four pending 2773 * evens on ffs->ev.types queue. This is important because the queue 2774 * has space for four elements only and __ffs_ep0_read_events function 2775 * depends on that limit as well. If more event types are added, those 2776 * limits have to be revisited or guaranteed to still hold. 2777 */ 2778 switch (type) { 2779 case FUNCTIONFS_RESUME: 2780 rem_type2 = FUNCTIONFS_SUSPEND; 2781 fallthrough; 2782 case FUNCTIONFS_SUSPEND: 2783 case FUNCTIONFS_SETUP: 2784 rem_type1 = type; 2785 /* Discard all similar events */ 2786 break; 2787 2788 case FUNCTIONFS_BIND: 2789 case FUNCTIONFS_UNBIND: 2790 case FUNCTIONFS_DISABLE: 2791 case FUNCTIONFS_ENABLE: 2792 /* Discard everything other then power management. */ 2793 rem_type1 = FUNCTIONFS_SUSPEND; 2794 rem_type2 = FUNCTIONFS_RESUME; 2795 neg = 1; 2796 break; 2797 2798 default: 2799 WARN(1, "%d: unknown event, this should not happen\n", type); 2800 return; 2801 } 2802 2803 { 2804 u8 *ev = ffs->ev.types, *out = ev; 2805 unsigned n = ffs->ev.count; 2806 for (; n; --n, ++ev) 2807 if ((*ev == rem_type1 || *ev == rem_type2) == neg) 2808 *out++ = *ev; 2809 else 2810 pr_vdebug("purging event %d\n", *ev); 2811 ffs->ev.count = out - ffs->ev.types; 2812 } 2813 2814 pr_vdebug("adding event %d\n", type); 2815 ffs->ev.types[ffs->ev.count++] = type; 2816 wake_up_locked(&ffs->ev.waitq); 2817 if (ffs->ffs_eventfd) 2818 eventfd_signal(ffs->ffs_eventfd, 1); 2819 } 2820 2821 static void ffs_event_add(struct ffs_data *ffs, 2822 enum usb_functionfs_event_type type) 2823 { 2824 unsigned long flags; 2825 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 2826 __ffs_event_add(ffs, type); 2827 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 2828 } 2829 2830 /* Bind/unbind USB function hooks *******************************************/ 2831 2832 static int ffs_ep_addr2idx(struct ffs_data *ffs, u8 endpoint_address) 2833 { 2834 int i; 2835 2836 for (i = 1; i < ARRAY_SIZE(ffs->eps_addrmap); ++i) 2837 if (ffs->eps_addrmap[i] == endpoint_address) 2838 return i; 2839 return -ENOENT; 2840 } 2841 2842 static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep, 2843 struct usb_descriptor_header *desc, 2844 void *priv) 2845 { 2846 struct usb_endpoint_descriptor *ds = (void *)desc; 2847 struct ffs_function *func = priv; 2848 struct ffs_ep *ffs_ep; 2849 unsigned ep_desc_id; 2850 int idx; 2851 static const char *speed_names[] = { "full", "high", "super" }; 2852 2853 if (type != FFS_DESCRIPTOR) 2854 return 0; 2855 2856 /* 2857 * If ss_descriptors is not NULL, we are reading super speed 2858 * descriptors; if hs_descriptors is not NULL, we are reading high 2859 * speed descriptors; otherwise, we are reading full speed 2860 * descriptors. 2861 */ 2862 if (func->function.ss_descriptors) { 2863 ep_desc_id = 2; 2864 func->function.ss_descriptors[(long)valuep] = desc; 2865 } else if (func->function.hs_descriptors) { 2866 ep_desc_id = 1; 2867 func->function.hs_descriptors[(long)valuep] = desc; 2868 } else { 2869 ep_desc_id = 0; 2870 func->function.fs_descriptors[(long)valuep] = desc; 2871 } 2872 2873 if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) 2874 return 0; 2875 2876 idx = ffs_ep_addr2idx(func->ffs, ds->bEndpointAddress) - 1; 2877 if (idx < 0) 2878 return idx; 2879 2880 ffs_ep = func->eps + idx; 2881 2882 if (ffs_ep->descs[ep_desc_id]) { 2883 pr_err("two %sspeed descriptors for EP %d\n", 2884 speed_names[ep_desc_id], 2885 ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); 2886 return -EINVAL; 2887 } 2888 ffs_ep->descs[ep_desc_id] = ds; 2889 2890 ffs_dump_mem(": Original ep desc", ds, ds->bLength); 2891 if (ffs_ep->ep) { 2892 ds->bEndpointAddress = ffs_ep->descs[0]->bEndpointAddress; 2893 if (!ds->wMaxPacketSize) 2894 ds->wMaxPacketSize = ffs_ep->descs[0]->wMaxPacketSize; 2895 } else { 2896 struct usb_request *req; 2897 struct usb_ep *ep; 2898 u8 bEndpointAddress; 2899 u16 wMaxPacketSize; 2900 2901 /* 2902 * We back up bEndpointAddress because autoconfig overwrites 2903 * it with physical endpoint address. 2904 */ 2905 bEndpointAddress = ds->bEndpointAddress; 2906 /* 2907 * We back up wMaxPacketSize because autoconfig treats 2908 * endpoint descriptors as if they were full speed. 2909 */ 2910 wMaxPacketSize = ds->wMaxPacketSize; 2911 pr_vdebug("autoconfig\n"); 2912 ep = usb_ep_autoconfig(func->gadget, ds); 2913 if (!ep) 2914 return -ENOTSUPP; 2915 ep->driver_data = func->eps + idx; 2916 2917 req = usb_ep_alloc_request(ep, GFP_KERNEL); 2918 if (!req) 2919 return -ENOMEM; 2920 2921 ffs_ep->ep = ep; 2922 ffs_ep->req = req; 2923 func->eps_revmap[ds->bEndpointAddress & 2924 USB_ENDPOINT_NUMBER_MASK] = idx + 1; 2925 /* 2926 * If we use virtual address mapping, we restore 2927 * original bEndpointAddress value. 2928 */ 2929 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 2930 ds->bEndpointAddress = bEndpointAddress; 2931 /* 2932 * Restore wMaxPacketSize which was potentially 2933 * overwritten by autoconfig. 2934 */ 2935 ds->wMaxPacketSize = wMaxPacketSize; 2936 } 2937 ffs_dump_mem(": Rewritten ep desc", ds, ds->bLength); 2938 2939 return 0; 2940 } 2941 2942 static int __ffs_func_bind_do_nums(enum ffs_entity_type type, u8 *valuep, 2943 struct usb_descriptor_header *desc, 2944 void *priv) 2945 { 2946 struct ffs_function *func = priv; 2947 unsigned idx; 2948 u8 newValue; 2949 2950 switch (type) { 2951 default: 2952 case FFS_DESCRIPTOR: 2953 /* Handled in previous pass by __ffs_func_bind_do_descs() */ 2954 return 0; 2955 2956 case FFS_INTERFACE: 2957 idx = *valuep; 2958 if (func->interfaces_nums[idx] < 0) { 2959 int id = usb_interface_id(func->conf, &func->function); 2960 if (id < 0) 2961 return id; 2962 func->interfaces_nums[idx] = id; 2963 } 2964 newValue = func->interfaces_nums[idx]; 2965 break; 2966 2967 case FFS_STRING: 2968 /* String' IDs are allocated when fsf_data is bound to cdev */ 2969 newValue = func->ffs->stringtabs[0]->strings[*valuep - 1].id; 2970 break; 2971 2972 case FFS_ENDPOINT: 2973 /* 2974 * USB_DT_ENDPOINT are handled in 2975 * __ffs_func_bind_do_descs(). 2976 */ 2977 if (desc->bDescriptorType == USB_DT_ENDPOINT) 2978 return 0; 2979 2980 idx = (*valuep & USB_ENDPOINT_NUMBER_MASK) - 1; 2981 if (!func->eps[idx].ep) 2982 return -EINVAL; 2983 2984 { 2985 struct usb_endpoint_descriptor **descs; 2986 descs = func->eps[idx].descs; 2987 newValue = descs[descs[0] ? 0 : 1]->bEndpointAddress; 2988 } 2989 break; 2990 } 2991 2992 pr_vdebug("%02x -> %02x\n", *valuep, newValue); 2993 *valuep = newValue; 2994 return 0; 2995 } 2996 2997 static int __ffs_func_bind_do_os_desc(enum ffs_os_desc_type type, 2998 struct usb_os_desc_header *h, void *data, 2999 unsigned len, void *priv) 3000 { 3001 struct ffs_function *func = priv; 3002 u8 length = 0; 3003 3004 switch (type) { 3005 case FFS_OS_DESC_EXT_COMPAT: { 3006 struct usb_ext_compat_desc *desc = data; 3007 struct usb_os_desc_table *t; 3008 3009 t = &func->function.os_desc_table[desc->bFirstInterfaceNumber]; 3010 t->if_id = func->interfaces_nums[desc->bFirstInterfaceNumber]; 3011 memcpy(t->os_desc->ext_compat_id, &desc->CompatibleID, 3012 ARRAY_SIZE(desc->CompatibleID) + 3013 ARRAY_SIZE(desc->SubCompatibleID)); 3014 length = sizeof(*desc); 3015 } 3016 break; 3017 case FFS_OS_DESC_EXT_PROP: { 3018 struct usb_ext_prop_desc *desc = data; 3019 struct usb_os_desc_table *t; 3020 struct usb_os_desc_ext_prop *ext_prop; 3021 char *ext_prop_name; 3022 char *ext_prop_data; 3023 3024 t = &func->function.os_desc_table[h->interface]; 3025 t->if_id = func->interfaces_nums[h->interface]; 3026 3027 ext_prop = func->ffs->ms_os_descs_ext_prop_avail; 3028 func->ffs->ms_os_descs_ext_prop_avail += sizeof(*ext_prop); 3029 3030 ext_prop->type = le32_to_cpu(desc->dwPropertyDataType); 3031 ext_prop->name_len = le16_to_cpu(desc->wPropertyNameLength); 3032 ext_prop->data_len = le32_to_cpu(*(__le32 *) 3033 usb_ext_prop_data_len_ptr(data, ext_prop->name_len)); 3034 length = ext_prop->name_len + ext_prop->data_len + 14; 3035 3036 ext_prop_name = func->ffs->ms_os_descs_ext_prop_name_avail; 3037 func->ffs->ms_os_descs_ext_prop_name_avail += 3038 ext_prop->name_len; 3039 3040 ext_prop_data = func->ffs->ms_os_descs_ext_prop_data_avail; 3041 func->ffs->ms_os_descs_ext_prop_data_avail += 3042 ext_prop->data_len; 3043 memcpy(ext_prop_data, 3044 usb_ext_prop_data_ptr(data, ext_prop->name_len), 3045 ext_prop->data_len); 3046 /* unicode data reported to the host as "WCHAR"s */ 3047 switch (ext_prop->type) { 3048 case USB_EXT_PROP_UNICODE: 3049 case USB_EXT_PROP_UNICODE_ENV: 3050 case USB_EXT_PROP_UNICODE_LINK: 3051 case USB_EXT_PROP_UNICODE_MULTI: 3052 ext_prop->data_len *= 2; 3053 break; 3054 } 3055 ext_prop->data = ext_prop_data; 3056 3057 memcpy(ext_prop_name, usb_ext_prop_name_ptr(data), 3058 ext_prop->name_len); 3059 /* property name reported to the host as "WCHAR"s */ 3060 ext_prop->name_len *= 2; 3061 ext_prop->name = ext_prop_name; 3062 3063 t->os_desc->ext_prop_len += 3064 ext_prop->name_len + ext_prop->data_len + 14; 3065 ++t->os_desc->ext_prop_count; 3066 list_add_tail(&ext_prop->entry, &t->os_desc->ext_prop); 3067 } 3068 break; 3069 default: 3070 pr_vdebug("unknown descriptor: %d\n", type); 3071 } 3072 3073 return length; 3074 } 3075 3076 static inline struct f_fs_opts *ffs_do_functionfs_bind(struct usb_function *f, 3077 struct usb_configuration *c) 3078 { 3079 struct ffs_function *func = ffs_func_from_usb(f); 3080 struct f_fs_opts *ffs_opts = 3081 container_of(f->fi, struct f_fs_opts, func_inst); 3082 struct ffs_data *ffs_data; 3083 int ret; 3084 3085 ENTER(); 3086 3087 /* 3088 * Legacy gadget triggers binding in functionfs_ready_callback, 3089 * which already uses locking; taking the same lock here would 3090 * cause a deadlock. 3091 * 3092 * Configfs-enabled gadgets however do need ffs_dev_lock. 3093 */ 3094 if (!ffs_opts->no_configfs) 3095 ffs_dev_lock(); 3096 ret = ffs_opts->dev->desc_ready ? 0 : -ENODEV; 3097 ffs_data = ffs_opts->dev->ffs_data; 3098 if (!ffs_opts->no_configfs) 3099 ffs_dev_unlock(); 3100 if (ret) 3101 return ERR_PTR(ret); 3102 3103 func->ffs = ffs_data; 3104 func->conf = c; 3105 func->gadget = c->cdev->gadget; 3106 3107 /* 3108 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 3109 * configurations are bound in sequence with list_for_each_entry, 3110 * in each configuration its functions are bound in sequence 3111 * with list_for_each_entry, so we assume no race condition 3112 * with regard to ffs_opts->bound access 3113 */ 3114 if (!ffs_opts->refcnt) { 3115 ret = functionfs_bind(func->ffs, c->cdev); 3116 if (ret) 3117 return ERR_PTR(ret); 3118 } 3119 ffs_opts->refcnt++; 3120 func->function.strings = func->ffs->stringtabs; 3121 3122 return ffs_opts; 3123 } 3124 3125 static int _ffs_func_bind(struct usb_configuration *c, 3126 struct usb_function *f) 3127 { 3128 struct ffs_function *func = ffs_func_from_usb(f); 3129 struct ffs_data *ffs = func->ffs; 3130 3131 const int full = !!func->ffs->fs_descs_count; 3132 const int high = !!func->ffs->hs_descs_count; 3133 const int super = !!func->ffs->ss_descs_count; 3134 3135 int fs_len, hs_len, ss_len, ret, i; 3136 struct ffs_ep *eps_ptr; 3137 3138 /* Make it a single chunk, less management later on */ 3139 vla_group(d); 3140 vla_item_with_sz(d, struct ffs_ep, eps, ffs->eps_count); 3141 vla_item_with_sz(d, struct usb_descriptor_header *, fs_descs, 3142 full ? ffs->fs_descs_count + 1 : 0); 3143 vla_item_with_sz(d, struct usb_descriptor_header *, hs_descs, 3144 high ? ffs->hs_descs_count + 1 : 0); 3145 vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs, 3146 super ? ffs->ss_descs_count + 1 : 0); 3147 vla_item_with_sz(d, short, inums, ffs->interfaces_count); 3148 vla_item_with_sz(d, struct usb_os_desc_table, os_desc_table, 3149 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3150 vla_item_with_sz(d, char[16], ext_compat, 3151 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3152 vla_item_with_sz(d, struct usb_os_desc, os_desc, 3153 c->cdev->use_os_string ? ffs->interfaces_count : 0); 3154 vla_item_with_sz(d, struct usb_os_desc_ext_prop, ext_prop, 3155 ffs->ms_os_descs_ext_prop_count); 3156 vla_item_with_sz(d, char, ext_prop_name, 3157 ffs->ms_os_descs_ext_prop_name_len); 3158 vla_item_with_sz(d, char, ext_prop_data, 3159 ffs->ms_os_descs_ext_prop_data_len); 3160 vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length); 3161 char *vlabuf; 3162 3163 ENTER(); 3164 3165 /* Has descriptors only for speeds gadget does not support */ 3166 if (!(full | high | super)) 3167 return -ENOTSUPP; 3168 3169 /* Allocate a single chunk, less management later on */ 3170 vlabuf = kzalloc(vla_group_size(d), GFP_KERNEL); 3171 if (!vlabuf) 3172 return -ENOMEM; 3173 3174 ffs->ms_os_descs_ext_prop_avail = vla_ptr(vlabuf, d, ext_prop); 3175 ffs->ms_os_descs_ext_prop_name_avail = 3176 vla_ptr(vlabuf, d, ext_prop_name); 3177 ffs->ms_os_descs_ext_prop_data_avail = 3178 vla_ptr(vlabuf, d, ext_prop_data); 3179 3180 /* Copy descriptors */ 3181 memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs, 3182 ffs->raw_descs_length); 3183 3184 memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz); 3185 eps_ptr = vla_ptr(vlabuf, d, eps); 3186 for (i = 0; i < ffs->eps_count; i++) 3187 eps_ptr[i].num = -1; 3188 3189 /* Save pointers 3190 * d_eps == vlabuf, func->eps used to kfree vlabuf later 3191 */ 3192 func->eps = vla_ptr(vlabuf, d, eps); 3193 func->interfaces_nums = vla_ptr(vlabuf, d, inums); 3194 3195 /* 3196 * Go through all the endpoint descriptors and allocate 3197 * endpoints first, so that later we can rewrite the endpoint 3198 * numbers without worrying that it may be described later on. 3199 */ 3200 if (full) { 3201 func->function.fs_descriptors = vla_ptr(vlabuf, d, fs_descs); 3202 fs_len = ffs_do_descs(ffs->fs_descs_count, 3203 vla_ptr(vlabuf, d, raw_descs), 3204 d_raw_descs__sz, 3205 __ffs_func_bind_do_descs, func); 3206 if (fs_len < 0) { 3207 ret = fs_len; 3208 goto error; 3209 } 3210 } else { 3211 fs_len = 0; 3212 } 3213 3214 if (high) { 3215 func->function.hs_descriptors = vla_ptr(vlabuf, d, hs_descs); 3216 hs_len = ffs_do_descs(ffs->hs_descs_count, 3217 vla_ptr(vlabuf, d, raw_descs) + fs_len, 3218 d_raw_descs__sz - fs_len, 3219 __ffs_func_bind_do_descs, func); 3220 if (hs_len < 0) { 3221 ret = hs_len; 3222 goto error; 3223 } 3224 } else { 3225 hs_len = 0; 3226 } 3227 3228 if (super) { 3229 func->function.ss_descriptors = func->function.ssp_descriptors = 3230 vla_ptr(vlabuf, d, ss_descs); 3231 ss_len = ffs_do_descs(ffs->ss_descs_count, 3232 vla_ptr(vlabuf, d, raw_descs) + fs_len + hs_len, 3233 d_raw_descs__sz - fs_len - hs_len, 3234 __ffs_func_bind_do_descs, func); 3235 if (ss_len < 0) { 3236 ret = ss_len; 3237 goto error; 3238 } 3239 } else { 3240 ss_len = 0; 3241 } 3242 3243 /* 3244 * Now handle interface numbers allocation and interface and 3245 * endpoint numbers rewriting. We can do that in one go 3246 * now. 3247 */ 3248 ret = ffs_do_descs(ffs->fs_descs_count + 3249 (high ? ffs->hs_descs_count : 0) + 3250 (super ? ffs->ss_descs_count : 0), 3251 vla_ptr(vlabuf, d, raw_descs), d_raw_descs__sz, 3252 __ffs_func_bind_do_nums, func); 3253 if (ret < 0) 3254 goto error; 3255 3256 func->function.os_desc_table = vla_ptr(vlabuf, d, os_desc_table); 3257 if (c->cdev->use_os_string) { 3258 for (i = 0; i < ffs->interfaces_count; ++i) { 3259 struct usb_os_desc *desc; 3260 3261 desc = func->function.os_desc_table[i].os_desc = 3262 vla_ptr(vlabuf, d, os_desc) + 3263 i * sizeof(struct usb_os_desc); 3264 desc->ext_compat_id = 3265 vla_ptr(vlabuf, d, ext_compat) + i * 16; 3266 INIT_LIST_HEAD(&desc->ext_prop); 3267 } 3268 ret = ffs_do_os_descs(ffs->ms_os_descs_count, 3269 vla_ptr(vlabuf, d, raw_descs) + 3270 fs_len + hs_len + ss_len, 3271 d_raw_descs__sz - fs_len - hs_len - 3272 ss_len, 3273 __ffs_func_bind_do_os_desc, func); 3274 if (ret < 0) 3275 goto error; 3276 } 3277 func->function.os_desc_n = 3278 c->cdev->use_os_string ? ffs->interfaces_count : 0; 3279 3280 /* And we're done */ 3281 ffs_event_add(ffs, FUNCTIONFS_BIND); 3282 return 0; 3283 3284 error: 3285 /* XXX Do we need to release all claimed endpoints here? */ 3286 return ret; 3287 } 3288 3289 static int ffs_func_bind(struct usb_configuration *c, 3290 struct usb_function *f) 3291 { 3292 struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c); 3293 struct ffs_function *func = ffs_func_from_usb(f); 3294 int ret; 3295 3296 if (IS_ERR(ffs_opts)) 3297 return PTR_ERR(ffs_opts); 3298 3299 ret = _ffs_func_bind(c, f); 3300 if (ret && !--ffs_opts->refcnt) 3301 functionfs_unbind(func->ffs); 3302 3303 return ret; 3304 } 3305 3306 3307 /* Other USB function hooks *************************************************/ 3308 3309 static void ffs_reset_work(struct work_struct *work) 3310 { 3311 struct ffs_data *ffs = container_of(work, 3312 struct ffs_data, reset_work); 3313 ffs_data_reset(ffs); 3314 } 3315 3316 static int ffs_func_set_alt(struct usb_function *f, 3317 unsigned interface, unsigned alt) 3318 { 3319 struct ffs_function *func = ffs_func_from_usb(f); 3320 struct ffs_data *ffs = func->ffs; 3321 int ret = 0, intf; 3322 3323 if (alt != (unsigned)-1) { 3324 intf = ffs_func_revmap_intf(func, interface); 3325 if (intf < 0) 3326 return intf; 3327 } 3328 3329 if (ffs->func) 3330 ffs_func_eps_disable(ffs->func); 3331 3332 if (ffs->state == FFS_DEACTIVATED) { 3333 ffs->state = FFS_CLOSING; 3334 INIT_WORK(&ffs->reset_work, ffs_reset_work); 3335 schedule_work(&ffs->reset_work); 3336 return -ENODEV; 3337 } 3338 3339 if (ffs->state != FFS_ACTIVE) 3340 return -ENODEV; 3341 3342 if (alt == (unsigned)-1) { 3343 ffs->func = NULL; 3344 ffs_event_add(ffs, FUNCTIONFS_DISABLE); 3345 return 0; 3346 } 3347 3348 ffs->func = func; 3349 ret = ffs_func_eps_enable(func); 3350 if (ret >= 0) 3351 ffs_event_add(ffs, FUNCTIONFS_ENABLE); 3352 return ret; 3353 } 3354 3355 static void ffs_func_disable(struct usb_function *f) 3356 { 3357 ffs_func_set_alt(f, 0, (unsigned)-1); 3358 } 3359 3360 static int ffs_func_setup(struct usb_function *f, 3361 const struct usb_ctrlrequest *creq) 3362 { 3363 struct ffs_function *func = ffs_func_from_usb(f); 3364 struct ffs_data *ffs = func->ffs; 3365 unsigned long flags; 3366 int ret; 3367 3368 ENTER(); 3369 3370 pr_vdebug("creq->bRequestType = %02x\n", creq->bRequestType); 3371 pr_vdebug("creq->bRequest = %02x\n", creq->bRequest); 3372 pr_vdebug("creq->wValue = %04x\n", le16_to_cpu(creq->wValue)); 3373 pr_vdebug("creq->wIndex = %04x\n", le16_to_cpu(creq->wIndex)); 3374 pr_vdebug("creq->wLength = %04x\n", le16_to_cpu(creq->wLength)); 3375 3376 /* 3377 * Most requests directed to interface go through here 3378 * (notable exceptions are set/get interface) so we need to 3379 * handle them. All other either handled by composite or 3380 * passed to usb_configuration->setup() (if one is set). No 3381 * matter, we will handle requests directed to endpoint here 3382 * as well (as it's straightforward). Other request recipient 3383 * types are only handled when the user flag FUNCTIONFS_ALL_CTRL_RECIP 3384 * is being used. 3385 */ 3386 if (ffs->state != FFS_ACTIVE) 3387 return -ENODEV; 3388 3389 switch (creq->bRequestType & USB_RECIP_MASK) { 3390 case USB_RECIP_INTERFACE: 3391 ret = ffs_func_revmap_intf(func, le16_to_cpu(creq->wIndex)); 3392 if (ret < 0) 3393 return ret; 3394 break; 3395 3396 case USB_RECIP_ENDPOINT: 3397 ret = ffs_func_revmap_ep(func, le16_to_cpu(creq->wIndex)); 3398 if (ret < 0) 3399 return ret; 3400 if (func->ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR) 3401 ret = func->ffs->eps_addrmap[ret]; 3402 break; 3403 3404 default: 3405 if (func->ffs->user_flags & FUNCTIONFS_ALL_CTRL_RECIP) 3406 ret = le16_to_cpu(creq->wIndex); 3407 else 3408 return -EOPNOTSUPP; 3409 } 3410 3411 spin_lock_irqsave(&ffs->ev.waitq.lock, flags); 3412 ffs->ev.setup = *creq; 3413 ffs->ev.setup.wIndex = cpu_to_le16(ret); 3414 __ffs_event_add(ffs, FUNCTIONFS_SETUP); 3415 spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); 3416 3417 return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; 3418 } 3419 3420 static bool ffs_func_req_match(struct usb_function *f, 3421 const struct usb_ctrlrequest *creq, 3422 bool config0) 3423 { 3424 struct ffs_function *func = ffs_func_from_usb(f); 3425 3426 if (config0 && !(func->ffs->user_flags & FUNCTIONFS_CONFIG0_SETUP)) 3427 return false; 3428 3429 switch (creq->bRequestType & USB_RECIP_MASK) { 3430 case USB_RECIP_INTERFACE: 3431 return (ffs_func_revmap_intf(func, 3432 le16_to_cpu(creq->wIndex)) >= 0); 3433 case USB_RECIP_ENDPOINT: 3434 return (ffs_func_revmap_ep(func, 3435 le16_to_cpu(creq->wIndex)) >= 0); 3436 default: 3437 return (bool) (func->ffs->user_flags & 3438 FUNCTIONFS_ALL_CTRL_RECIP); 3439 } 3440 } 3441 3442 static void ffs_func_suspend(struct usb_function *f) 3443 { 3444 ENTER(); 3445 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_SUSPEND); 3446 } 3447 3448 static void ffs_func_resume(struct usb_function *f) 3449 { 3450 ENTER(); 3451 ffs_event_add(ffs_func_from_usb(f)->ffs, FUNCTIONFS_RESUME); 3452 } 3453 3454 3455 /* Endpoint and interface numbers reverse mapping ***************************/ 3456 3457 static int ffs_func_revmap_ep(struct ffs_function *func, u8 num) 3458 { 3459 num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK]; 3460 return num ? num : -EDOM; 3461 } 3462 3463 static int ffs_func_revmap_intf(struct ffs_function *func, u8 intf) 3464 { 3465 short *nums = func->interfaces_nums; 3466 unsigned count = func->ffs->interfaces_count; 3467 3468 for (; count; --count, ++nums) { 3469 if (*nums >= 0 && *nums == intf) 3470 return nums - func->interfaces_nums; 3471 } 3472 3473 return -EDOM; 3474 } 3475 3476 3477 /* Devices management *******************************************************/ 3478 3479 static LIST_HEAD(ffs_devices); 3480 3481 static struct ffs_dev *_ffs_do_find_dev(const char *name) 3482 { 3483 struct ffs_dev *dev; 3484 3485 if (!name) 3486 return NULL; 3487 3488 list_for_each_entry(dev, &ffs_devices, entry) { 3489 if (strcmp(dev->name, name) == 0) 3490 return dev; 3491 } 3492 3493 return NULL; 3494 } 3495 3496 /* 3497 * ffs_lock must be taken by the caller of this function 3498 */ 3499 static struct ffs_dev *_ffs_get_single_dev(void) 3500 { 3501 struct ffs_dev *dev; 3502 3503 if (list_is_singular(&ffs_devices)) { 3504 dev = list_first_entry(&ffs_devices, struct ffs_dev, entry); 3505 if (dev->single) 3506 return dev; 3507 } 3508 3509 return NULL; 3510 } 3511 3512 /* 3513 * ffs_lock must be taken by the caller of this function 3514 */ 3515 static struct ffs_dev *_ffs_find_dev(const char *name) 3516 { 3517 struct ffs_dev *dev; 3518 3519 dev = _ffs_get_single_dev(); 3520 if (dev) 3521 return dev; 3522 3523 return _ffs_do_find_dev(name); 3524 } 3525 3526 /* Configfs support *********************************************************/ 3527 3528 static inline struct f_fs_opts *to_ffs_opts(struct config_item *item) 3529 { 3530 return container_of(to_config_group(item), struct f_fs_opts, 3531 func_inst.group); 3532 } 3533 3534 static void ffs_attr_release(struct config_item *item) 3535 { 3536 struct f_fs_opts *opts = to_ffs_opts(item); 3537 3538 usb_put_function_instance(&opts->func_inst); 3539 } 3540 3541 static struct configfs_item_operations ffs_item_ops = { 3542 .release = ffs_attr_release, 3543 }; 3544 3545 static const struct config_item_type ffs_func_type = { 3546 .ct_item_ops = &ffs_item_ops, 3547 .ct_owner = THIS_MODULE, 3548 }; 3549 3550 3551 /* Function registration interface ******************************************/ 3552 3553 static void ffs_free_inst(struct usb_function_instance *f) 3554 { 3555 struct f_fs_opts *opts; 3556 3557 opts = to_f_fs_opts(f); 3558 ffs_release_dev(opts->dev); 3559 ffs_dev_lock(); 3560 _ffs_free_dev(opts->dev); 3561 ffs_dev_unlock(); 3562 kfree(opts); 3563 } 3564 3565 static int ffs_set_inst_name(struct usb_function_instance *fi, const char *name) 3566 { 3567 if (strlen(name) >= sizeof_field(struct ffs_dev, name)) 3568 return -ENAMETOOLONG; 3569 return ffs_name_dev(to_f_fs_opts(fi)->dev, name); 3570 } 3571 3572 static struct usb_function_instance *ffs_alloc_inst(void) 3573 { 3574 struct f_fs_opts *opts; 3575 struct ffs_dev *dev; 3576 3577 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 3578 if (!opts) 3579 return ERR_PTR(-ENOMEM); 3580 3581 opts->func_inst.set_inst_name = ffs_set_inst_name; 3582 opts->func_inst.free_func_inst = ffs_free_inst; 3583 ffs_dev_lock(); 3584 dev = _ffs_alloc_dev(); 3585 ffs_dev_unlock(); 3586 if (IS_ERR(dev)) { 3587 kfree(opts); 3588 return ERR_CAST(dev); 3589 } 3590 opts->dev = dev; 3591 dev->opts = opts; 3592 3593 config_group_init_type_name(&opts->func_inst.group, "", 3594 &ffs_func_type); 3595 return &opts->func_inst; 3596 } 3597 3598 static void ffs_free(struct usb_function *f) 3599 { 3600 kfree(ffs_func_from_usb(f)); 3601 } 3602 3603 static void ffs_func_unbind(struct usb_configuration *c, 3604 struct usb_function *f) 3605 { 3606 struct ffs_function *func = ffs_func_from_usb(f); 3607 struct ffs_data *ffs = func->ffs; 3608 struct f_fs_opts *opts = 3609 container_of(f->fi, struct f_fs_opts, func_inst); 3610 struct ffs_ep *ep = func->eps; 3611 unsigned count = ffs->eps_count; 3612 unsigned long flags; 3613 3614 ENTER(); 3615 if (ffs->func == func) { 3616 ffs_func_eps_disable(func); 3617 ffs->func = NULL; 3618 } 3619 3620 /* Drain any pending AIO completions */ 3621 drain_workqueue(ffs->io_completion_wq); 3622 3623 if (!--opts->refcnt) 3624 functionfs_unbind(ffs); 3625 3626 /* cleanup after autoconfig */ 3627 spin_lock_irqsave(&func->ffs->eps_lock, flags); 3628 while (count--) { 3629 if (ep->ep && ep->req) 3630 usb_ep_free_request(ep->ep, ep->req); 3631 ep->req = NULL; 3632 ++ep; 3633 } 3634 spin_unlock_irqrestore(&func->ffs->eps_lock, flags); 3635 kfree(func->eps); 3636 func->eps = NULL; 3637 /* 3638 * eps, descriptors and interfaces_nums are allocated in the 3639 * same chunk so only one free is required. 3640 */ 3641 func->function.fs_descriptors = NULL; 3642 func->function.hs_descriptors = NULL; 3643 func->function.ss_descriptors = NULL; 3644 func->function.ssp_descriptors = NULL; 3645 func->interfaces_nums = NULL; 3646 3647 ffs_event_add(ffs, FUNCTIONFS_UNBIND); 3648 } 3649 3650 static struct usb_function *ffs_alloc(struct usb_function_instance *fi) 3651 { 3652 struct ffs_function *func; 3653 3654 ENTER(); 3655 3656 func = kzalloc(sizeof(*func), GFP_KERNEL); 3657 if (!func) 3658 return ERR_PTR(-ENOMEM); 3659 3660 func->function.name = "Function FS Gadget"; 3661 3662 func->function.bind = ffs_func_bind; 3663 func->function.unbind = ffs_func_unbind; 3664 func->function.set_alt = ffs_func_set_alt; 3665 func->function.disable = ffs_func_disable; 3666 func->function.setup = ffs_func_setup; 3667 func->function.req_match = ffs_func_req_match; 3668 func->function.suspend = ffs_func_suspend; 3669 func->function.resume = ffs_func_resume; 3670 func->function.free_func = ffs_free; 3671 3672 return &func->function; 3673 } 3674 3675 /* 3676 * ffs_lock must be taken by the caller of this function 3677 */ 3678 static struct ffs_dev *_ffs_alloc_dev(void) 3679 { 3680 struct ffs_dev *dev; 3681 int ret; 3682 3683 if (_ffs_get_single_dev()) 3684 return ERR_PTR(-EBUSY); 3685 3686 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 3687 if (!dev) 3688 return ERR_PTR(-ENOMEM); 3689 3690 if (list_empty(&ffs_devices)) { 3691 ret = functionfs_init(); 3692 if (ret) { 3693 kfree(dev); 3694 return ERR_PTR(ret); 3695 } 3696 } 3697 3698 list_add(&dev->entry, &ffs_devices); 3699 3700 return dev; 3701 } 3702 3703 int ffs_name_dev(struct ffs_dev *dev, const char *name) 3704 { 3705 struct ffs_dev *existing; 3706 int ret = 0; 3707 3708 ffs_dev_lock(); 3709 3710 existing = _ffs_do_find_dev(name); 3711 if (!existing) 3712 strscpy(dev->name, name, ARRAY_SIZE(dev->name)); 3713 else if (existing != dev) 3714 ret = -EBUSY; 3715 3716 ffs_dev_unlock(); 3717 3718 return ret; 3719 } 3720 EXPORT_SYMBOL_GPL(ffs_name_dev); 3721 3722 int ffs_single_dev(struct ffs_dev *dev) 3723 { 3724 int ret; 3725 3726 ret = 0; 3727 ffs_dev_lock(); 3728 3729 if (!list_is_singular(&ffs_devices)) 3730 ret = -EBUSY; 3731 else 3732 dev->single = true; 3733 3734 ffs_dev_unlock(); 3735 return ret; 3736 } 3737 EXPORT_SYMBOL_GPL(ffs_single_dev); 3738 3739 /* 3740 * ffs_lock must be taken by the caller of this function 3741 */ 3742 static void _ffs_free_dev(struct ffs_dev *dev) 3743 { 3744 list_del(&dev->entry); 3745 3746 kfree(dev); 3747 if (list_empty(&ffs_devices)) 3748 functionfs_cleanup(); 3749 } 3750 3751 static int ffs_acquire_dev(const char *dev_name, struct ffs_data *ffs_data) 3752 { 3753 int ret = 0; 3754 struct ffs_dev *ffs_dev; 3755 3756 ENTER(); 3757 ffs_dev_lock(); 3758 3759 ffs_dev = _ffs_find_dev(dev_name); 3760 if (!ffs_dev) { 3761 ret = -ENOENT; 3762 } else if (ffs_dev->mounted) { 3763 ret = -EBUSY; 3764 } else if (ffs_dev->ffs_acquire_dev_callback && 3765 ffs_dev->ffs_acquire_dev_callback(ffs_dev)) { 3766 ret = -ENOENT; 3767 } else { 3768 ffs_dev->mounted = true; 3769 ffs_dev->ffs_data = ffs_data; 3770 ffs_data->private_data = ffs_dev; 3771 } 3772 3773 ffs_dev_unlock(); 3774 return ret; 3775 } 3776 3777 static void ffs_release_dev(struct ffs_dev *ffs_dev) 3778 { 3779 ENTER(); 3780 ffs_dev_lock(); 3781 3782 if (ffs_dev && ffs_dev->mounted) { 3783 ffs_dev->mounted = false; 3784 if (ffs_dev->ffs_data) { 3785 ffs_dev->ffs_data->private_data = NULL; 3786 ffs_dev->ffs_data = NULL; 3787 } 3788 3789 if (ffs_dev->ffs_release_dev_callback) 3790 ffs_dev->ffs_release_dev_callback(ffs_dev); 3791 } 3792 3793 ffs_dev_unlock(); 3794 } 3795 3796 static int ffs_ready(struct ffs_data *ffs) 3797 { 3798 struct ffs_dev *ffs_obj; 3799 int ret = 0; 3800 3801 ENTER(); 3802 ffs_dev_lock(); 3803 3804 ffs_obj = ffs->private_data; 3805 if (!ffs_obj) { 3806 ret = -EINVAL; 3807 goto done; 3808 } 3809 if (WARN_ON(ffs_obj->desc_ready)) { 3810 ret = -EBUSY; 3811 goto done; 3812 } 3813 3814 ffs_obj->desc_ready = true; 3815 3816 if (ffs_obj->ffs_ready_callback) { 3817 ret = ffs_obj->ffs_ready_callback(ffs); 3818 if (ret) 3819 goto done; 3820 } 3821 3822 set_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags); 3823 done: 3824 ffs_dev_unlock(); 3825 return ret; 3826 } 3827 3828 static void ffs_closed(struct ffs_data *ffs) 3829 { 3830 struct ffs_dev *ffs_obj; 3831 struct f_fs_opts *opts; 3832 struct config_item *ci; 3833 3834 ENTER(); 3835 ffs_dev_lock(); 3836 3837 ffs_obj = ffs->private_data; 3838 if (!ffs_obj) 3839 goto done; 3840 3841 ffs_obj->desc_ready = false; 3842 3843 if (test_and_clear_bit(FFS_FL_CALL_CLOSED_CALLBACK, &ffs->flags) && 3844 ffs_obj->ffs_closed_callback) 3845 ffs_obj->ffs_closed_callback(ffs); 3846 3847 if (ffs_obj->opts) 3848 opts = ffs_obj->opts; 3849 else 3850 goto done; 3851 3852 if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent 3853 || !kref_read(&opts->func_inst.group.cg_item.ci_kref)) 3854 goto done; 3855 3856 ci = opts->func_inst.group.cg_item.ci_parent->ci_parent; 3857 ffs_dev_unlock(); 3858 3859 if (test_bit(FFS_FL_BOUND, &ffs->flags)) 3860 unregister_gadget_item(ci); 3861 return; 3862 done: 3863 ffs_dev_unlock(); 3864 } 3865 3866 /* Misc helper functions ****************************************************/ 3867 3868 static int ffs_mutex_lock(struct mutex *mutex, unsigned nonblock) 3869 { 3870 return nonblock 3871 ? mutex_trylock(mutex) ? 0 : -EAGAIN 3872 : mutex_lock_interruptible(mutex); 3873 } 3874 3875 static char *ffs_prepare_buffer(const char __user *buf, size_t len) 3876 { 3877 char *data; 3878 3879 if (!len) 3880 return NULL; 3881 3882 data = memdup_user(buf, len); 3883 if (IS_ERR(data)) 3884 return data; 3885 3886 pr_vdebug("Buffer from user space:\n"); 3887 ffs_dump_mem("", data, len); 3888 3889 return data; 3890 } 3891 3892 DECLARE_USB_FUNCTION_INIT(ffs, ffs_alloc_inst, ffs_alloc); 3893 MODULE_LICENSE("GPL"); 3894 MODULE_AUTHOR("Michal Nazarewicz"); 3895